Saturnalia was a wild carnival, as well as a time to mark the passing of the seasons. The solar declination (subpolar point) on June 21st is 2. Nope! r,mm(g/cm3)r,mm(g/cm3)060.622.70.125.810.792.190.245.140.862.10.364.290.932.040.493.3912. Whether you need help solving quadratic equations, inspiration for the upcoming science fair or the latest update on a major storm, Sciencing is here to help. During Saturnalia festivities, Romans enjoyed banquets, gambling, jokes, gifts, and a tradition of usurping strict social structures. Solar declination is the angle between the Sun's rays and the plane of the Earth's Equator, and its value depends on where Earth is in its orbit around the Sun. During the equinoxes, solar declination is 0. As specified in the following table, a manufactured spherical particle has a density that varies as a function of the distance from its center (r = 0): r,mm00.120.240.360.49(g/cm3)65.815.144.293.39r,mm0.620.790.860.931(g/cm3)2.72.192.12.042\begin{array}{llllll}{\mathrm{r,mm}} & {0} & {0.12} & {0.24} & {0.36} & {0.49} \\ {\rho\left(\mathrm{g / c m^{3}}\right)} & {6} & {5.81} & {5.14} & {4.29} & {3.39} \\ {\mathrm{r,mm}} & {0.62} & {0.79} & {0.86} & {0.93} & {1} \\ {\rho\left(\mathrm{g / c m^{3}}\right)} & {2.7} & {2.19} & {2.1} & {2.04} & {2}\end{array} The suns vertical rays strike the Tropic of Cancer, 23.5 north of the Equator, during the June solstice. Declination angle vary between 23.45o on June to -23.45o on December 21. So, whether you are in Los Angeles, Phoenix, Denver, or Boston, the solar declination will be the same for the same UTC time. Lunar Living Astrology & Moon Tracks Astrology - Charts, tables, and graphs on this page are created exclusively for this website. sun reaches its highest point in the sky at noon on June 21, the These two days are called equinoxes. The northernmost latitude in New York is 45 degrees, so the Declination, Latitude, & Earth Illumination. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource. For information on user permissions, please read our Terms of Service. So the above equation can have up to 2.0 of error, about four times the Sun's angular width, depending on how it is used. The solar declination angle at the vernal equinox is 0. summer "solstice". Write this number down. Like the solstices, equinoxes are historic markers of seasonal change. This enables the analemma to be used to make simple analog computations of quantities such as the times and azimuths of sunrise and sunset. google_ad_width = 468; (0.5 point) What causes seasons on earth? This is the June solstice, after which the subsolar point begins to migrate south. These accuracies are compared to NOAA's advanced calculations[13][14] which are based on the 1999 Jean Meeus algorithm that is accurate to within 0.01. Because of this tilt, the equator of the earth and the rays of the sun always make some angle between them. It will be different every single day. She or he will best know the preferred format. The declination reaches a maximum of 23.45 on June 22 (summer solstice in the northern hemisphere) and a minimum of -23.45 on December 21-22 (winter solstice in the northern hemisphere). The subsolar point will cross every latitude between these extremes twice every year. The value of each declination is taken to 1 decimal place which is compatible with the expected accuracy of a clinometer reading. Seen from anywhere between 23.5 degrees south latitude and the Any interactives on this page can only be played while you are visiting our website. Finally, the scent of pine, a sturdy evergreen, symbolizes autumn and the slow onset of the cold season on the Korean peninsula. i.e., June 21 and December 21. The December solstice is the winter solstice in the Northern Hemisphere and the summer solstice in the Southern.. Summer Solstice, where the Sun is about 23.5 degrees north of the On June 21, the summer solstice for the Northern Hemisphere, the northern end of the axis of rotation is pointing most directly toward the Sun, and the declination is 23.5. Az & El both report dark after astronomical twilight. At the North Pole and South Pole, the solstices mark the time when the sun is highest or lowest in the sky. It oscillates between these two numbers; it will never cross 23.44 or fall behind 23.44. If your sun sign is. Since the Earth rotates at a mean speed of one degree every four minutes, relative to the Sun, this 16-minute displacement corresponds to a shift eastward or westward of about four degrees in the apparent position of the Sun, compared with its mean position. The solar declination angle is gradually changed from +23.45 (or North) on June 21, to 23.45 (or South) on December 21. With the help of SolarSena, the author intends to promote solar power and wants to spread the use of clean technology. The September equinox is the autumnal equinox in the Northern Hemisphere and the vernal in the Southern. Caricorn on the Spring Equinox? (The Equator, of course, is 0 latitude.) 1. the PSA algorithm below) is up to 1. However, the angle restricts itself between 23.44 and 23.44. A. And it is negative for the rest of the portion of the year. 2023 Leaf Group Ltd. / Leaf Group Media, All Rights Reserved. This equation treats the Earth's orbit as being round rather than its true elliptical shape along with some other approximations . the days part of the ordinal date 1). If a media asset is downloadable, a download button appears in the corner of the media viewer. True or False: The main form of energy output emitted from Earth is longwave, infrared heat energy. Obliquity and Earths Illumination | Astronomical Seasons and Illumination. It is the same across the earth for a given moment of time. Select the date, time, and your time zone to compute the declination angle in the degree. The bite-sized food encourages sharing, and the rice and fillings are all harvested in late summer and autumn. Which statement about the Vernal Equinox is correct? On Earth, solstices are twice-yearly phenomena in which solar declination reaches the Tropic of Cancer in the north and the Tropic of Capricorn in the south. This is known as the Vernal or Spring Equinox. Pagans and neopagans, followers of early European religious traditions, still celebrate the winter solstice as a holiday called Yule. A solstice occurs when the declination is23.5 (June 21 and December 21, currently). For example, the number of days between January 1st and February 14th is 44. In other places, midwinter celebrations are the last festivals before the long famine months of winter. A true equinox would indicate 12 hours of both day and night. An overview of how the Suns energy is generated and how its thermal radiation illuminates and heats Earth. Whether you are at the poles or the equator, the angle of declination will not change for the same UTC time. During the June solstice (marked between June 20 and June 22), solar declination is about 23.5N (the Tropic of Cancer). Write down the result. Many of these traditions still survive in Europe and countries that have large populations with European (especially Scandinavian) heritage, such as Canada and the United States. Solarsena.com is enrolled in the Amazon Affiliate program. Solar energy that reaches Earth is called _____________. During an equinox, March 21 or September 22, the solar declination (referred to as declination from here on) is 0. In Finland, midsummer (Juhannus) celebrations include bonfires, saunas, and barbeques. Although the tilt of the Earth's axis changes slowly over thousands of years, on smaller timescales it seems perfectly consistent, and the solar declination can be calculated based on what day of the year it is. However, it differs slightly with local time zones. Any interactives on this page can only be played while you are visiting our website. During an equinox, solar declination is 0the Equatorand both the Northern and Southern Hemisphere receive equal sunlight.). Early Christians adopted the timing of Saturnalia for two of their most important seasons, Advent and Christmas. However, the Earth is tilted by 23.45 and the declination angle varies plus or minus this amount. Perhaps the most widespread and well-known equinoctial new year is Nowruz, the first day of the year in the Persian calendar. In this way, the equinoxes in polar regions signal the slow change from midnight sun to polar night. Midnight sun describes the phenomenon in which the sun never dips below the horizon, keeping the region bathed in sunlight 24 hours a day. Midsummer heralded the height of agricultural fertility and the slow onset of the harvestseason. The plot below gives the monthly variation of the elevation angle for Denver (39.74 N, 104.99 W) and Sydney (33.87 S, 151.21 E). Solar declination describes the latitude of Earth where the sun is directly overhead at noon. is the latitude of the location, is the solar declination angle (deg), . Check out our latest addition currently being tested. When you reach out to him or her, you will need the page title, URL, and the date you accessed the resource. We can calculate the solar declination angle using the following formula: In the above formula, d is the number of days since January 1st (UTC 00:00:00). The value of the declination angle is 23.44, the lowest, on December 21st (or 22nd). Since ancient times, many cultures have marked the solstices with holidays and festivals. 2. changes slowly from day to day and ranges from 23.5N Latitude (called the tropic of Cancer) on the A westward shift causes the sundial to be ahead of the clock. "equinoxes". For instance the SPA algorithm 2(http://www.psa.es/sdg/sunpos.htm) uses: dOmega=2.1429-0.0010394594*dElapsedJulianDays; dMeanLongitude = 4.8950630+ 0.017202791698*dElapsedJulianDays; // Radians dMeanAnomaly = 6.2400600+ 0.0172019699*dElapsedJulianDays; dEclipticLongitude = dMeanLongitude + 0.03341607*sin( dMeanAnomaly ) + 0.00034894*sin( 2*dMeanAnomaly )-0.0001134 -0.0000203*sin(dOmega); dEclipticObliquity = 0.4090928 - 6.2140e-9*dElapsedJulianDays +0.0000396*cos(dOmega); dSin_EclipticLongitude= sin( dEclipticLongitude ); dY = cos( dEclipticObliquity ) * dSin_EclipticLongitude; dRightAscension = atan2( dY,dX ); if( dRightAscension < 0.0 ) dRightAscension = dRightAscension + twopi; dDeclination = asin( sin( dEclipticObliquity )*dSin_EclipticLongitude ); dElapsedJulian days is the number of days since January 1, 2000 and dDeclination is the resulting declination. 23.5. From the first day of January until the final day of June, experiments are conducted on the constructed solar distillation apparatus with slope. This However, the annual number of cloudy days was 21 (about 6%) for the first group and almost twice (39) for the second . The Sun will never appear beyond the maximum declination of 23 degrees 27 minutes. Jupiter is likely to go out of bounds every six years, but does not always. For an interactive graph of solar declination, download the Sun-Earth Connection desktop app on the Software page, or download a PDF to print. Please consider helping us to decide.Moon Tracks and Lunar Living Survey. The solstices mark when the subsolar point reaches its northernmost and southernmost latitudes. QUESTION 3 Solar elevation angle plus always equals 90 degrees QUESTION 4 To find the the latitude where the sun is . solstice, the Sun shines most directly on the Tropic of Cancer, 23.5 degrees north of the equator, giving its most direct energy on Earth to the Northern Hemisphere. The equinoxes are the only time when both the Northern and Southern Hemispheresexperience roughly equal amounts of daytime and nighttime. The timing of equinoxes is determined by the planets axial tilt and orbital characteristics. As we can see from the above graph, the solar declination angle is positive from the vernal equinox to the autumnal equinoxi.e., March 20th to September 22nd (or 23rd). It will not change from place-to-place for the same UTC time. 1. In the northern hemisphere, the March equinox (March 20th) is called the spring or vernal equinox, and the September equinox (September 22nd (or 23rd)) is called the fall or autumnal equinox. The date of Easter, one of the most important holidays in the Christian calendar, is calculated using the March equinox. Sustainable and Stylish: How Solar-Powered Mason Jar Lights Can Transform Your Home or Outdoor Space, Testing Solar Panels: How to Ensure Optimal Performance, The Beginner's Guide to Using Camping Solar Panels on Your Next Trip, Using Solar Motion Sensor Lights for Sustainable Outdoor Lighting, Optimal Solar Panel Tilt Angle Calculator, The Beginners Guide to Using Camping Solar Panels on Your Next Trip, The Lowdown on Solar Panel Covers: Why You Need Them and How They Help, Arizona Solar Incentives: A Brief Introduction. If you have questions about licensing content on this page, please contact ngimagecollection@natgeo.com for more information and to obtain a license. The declination, in degrees, for any given day may be calculated in first approximation with the equation: The minus sign "-" represents the Southern declinations. The distance between the earth and the sun B. Elevation is measured in degrees up from the horizon. Seen from anywhere on the equator, the sun reaches its highest Every equinox, the light of the sun casts shadows down the steps of the pyramid, making it look like a slithering serpent. In the Southern Hemisphere, sun outages occur after the March equinox and before the September equinox. At lower values of in radians, sin() . After the September equinox, the subsolar point . The ancient Babylonian calendar began on the first full moon after the March equinox, and today, many cultural and religious calendars continue to celebrate new year in the spring. Outside of astronomy, tenths of a degree are more than sufficient for measurements. [11] An additional error of up to 0.5 can occur in all equations around the equinoxes if not using a decimal place when selecting N to adjust for the time after UT midnight for the beginning of that day. where the declination angle is the angle between the plane of the Earth's equator and the direction of the sun, and varies throughout the year. The answer depends on where on earth you live. Between the equator and 23.5 degrees north latitude, the If you are born in June, your sun sign is either Gemini (May 21 - June 21) or Cancer (June 21 - July 22). The declination reaches a maximum of 23.45 on June 22 (summer solstice in the northern hemisphere) and a minimum of -23.45 on December 21-22 (winter solstice in the northern hemisphere). Sun's Declination Table. The summer solstice is the longest day of the year, meaning it experiences the maximum intensity of the suns rays and has the most hours of sunlight. If you have any questions, please feel free to contact me at info@solarsena.com. Most cultural events associated with the September equinox are tied to autumnal harvest festivals. Solar declination describes the latitude of Earth where the sun is directly overhead at noon. On the gas giant Saturn, for example, equinoxes are particularly dramatic. The pattern repeats itself each year. for noon on the 1st January, N = 0, for noon on 2nd January, N = 1etc.. From the example, 54 times .9863 equals 53.2603. The declination angle becomes zero twice a year. When we see a month with a lot of red displayed, you can be certain that there will be some intense moments throughout that month. Which of the following parts of the electromagnetic spectrum represents the shortest wavelength? The declination angle can also be defined in other ways. Determine how many days have passed since January 1st. National Geographic Society is a 501 (c)(3) organization. During a solstice, which occurs around Dec. 21 and June 21 every year, the Earth's axis is positioned relative to the sun such that one hemisphere is closest to the sun and the other is farthest from the sun. Shadowy SnakeAncient Mayan architects may have honored the equinoxes in the design of the enormous stone pyramid nicknamed "El Castillo" at Chichen-Itza, Mexico. Its value depends on where Earth is in its orbit around the Sun. Since the main effect of this oscillation concerns time, it is called the equation of time, using the word "equation" in a somewhat archaic sense meaning "correction". When sunlight shines on the ground, it warms. See Answer Question: 1. At about 30 latitude, day is about eight minutes longer than night. Seen from anywhere between 23.5 degrees north latitude and the Notice that the declination changes very slowly near the solstices and most quickly around the equinoxes. We only require the number of days (d) to know the angle. The eccentricity varies very slowly over time, but for dates fairly close to the present, it can be considered to be constant. is the angle between the Suns rays and the plane of the Earths Equator. Solstices now mark the beginning of winter and summer, but because some ancient cultures only recognized these two seasons (there was no autumn or spring), the solstices occurred in the middle of the season. The solar declination angle changes time-to-time; it is not a constant number. During the December solstice (marked between December 20 and December 23), solar declination is about 23.5S (the Tropic of Capricorn). SongpyeonSongpyeon are an iconicfood associated with Chuseok, the Korean holiday around theSeptember equinox. The year has two equinoxes, which are the days on which the night and day are of equal length. Fewer events mark the September equinox. Sun. Some analemmas are marked to show the position of the Sun on the graph on various dates, a few days apart, throughout the year. In the play, fairies enchant two couples in a magical forestand haphazardly get enchanted themselves. The Equator, at 0 latitude, receives a maximum intensity of the suns rays all year. sun reaches its highest point in the sky at noon on December 21, Add ten to the number of days passed. You only need the date and time. The Sun's declination can be used, along with its right ascension, to calculate its azimuth and also its true elevation, which can then be corrected for refraction to give its apparent position.[2][14][18]. These equations assume the earth orbits around the sun in a perfect circle. The solar declination (subpolar point) on June 21st is 2. We can calculate the solar declination angle for a particular time from the former formula. In the northern hemisphere, the declination angle for the summer solstice is 23.44, while in the southern hemisphere, it is 23.44. Drawings of declination circles contain the visual and numerical information to understand and predict the Suns motion across the sky. This is largely due to atmospheric refraction. Due to atmospheric refraction, we are able to see the sun minutes before it actually rises and sets. Earth rotates around its own axis. Solar Declination (degrees): Solar Azimuth: Solar Elevation: cosine of solar zenith angle: Azimuth is measured in degrees clockwise from north. The solar declination angle reaches a maximum on June 20th (or 21st). If uncorrected, these mistakes are called \rule{1.5cm}{0.4pt} When a single nucleotide is changed, this is called a(n) \rule{1.5cm}{0.4pt}. /* 468x15, created 4/4/10 */ the change in declination for a range of days. The exact dates depend on exactly In Alpine and Germanic regions, summer solstice bonfires are so ingrained in the cultures they have their own name: Sonnwendfeuer. The declination of the Sun is the angle between the light rays from the Sun and the Earth's equator. Is it a coincidence that the declination ranges between 23.5, where 23.5 is the Earths obliquity? This day is named the June solstice. Obliquity is the angle between the planes of the Earths equator and its orbit around the Sun. Sometimes mistakes are made during DNA replication. Seasonal variation increases with latitude. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. The declination reaches its maximum value, +23 17', on 21 June (the summer solstice in the northern hemisphere, the winter solstice in the southern hemisphere). Following the example, adding 10 to 44 gives 54. For more than 3,000 years, Nowruz has been a religious holiday in Zoroastrianism, but today it is marked by secular celebrations throughout Eastern Europe and Central Asia. This is caused by the tilt of the Earth's axis, and also by changes in the speed of its orbital motion around the Sun produced by the elliptical shape of the orbit. Anequinoxis an event in which a planets subsolar point passes through its Equator. Haft-sin are seven symbolic foods associated with Nowruz, all beginning with the Arabic or Persian letter sin: sabze (sprouts, symbolizing rebirth); samanu (sweet pudding, symbolizing wealth); senjed (dried, date-like fruits, symbolizing love); seer (garlic, symbolizing health); seeb (apples, symbolizing beauty); somac (red sumac fruit, symbolizing the color of sunrise); and serkeh (vinegar, symbolizing age and wisdom). Another transition period is when planets transit over the equator which is referred to as zero degrees "0." Yom Kippur, the holiest day in the Jewish calendar, falls about 10 days after Rosh Hashanah. The Shalako midwinter dance is a custom among the Zuni peoples of what is now the Southwestern United States. The Sun's furthest north declination occurs on June 21 at the The value of is minimum when the cosine is equal to the positive one. 2. In many cultures, holidays surrounding midwinter are more prayerful than celebratorythey include cultures praying for survival through the dark and cold, as well as celebrating the spirit of cooperation that helps communities survive difficult times. A. Earth experiences astronomical seasons due to its obliquity. National Geographic Headquarters 1145 17th Street NW Washington, DC 20036. National Geographic Society is a 501 (c)(3) organization. You cannot download interactives. Atmospheric refraction also increases the disparity in the equinox length of day and night. Take note of dates that this is occurring as there will tend to be an extra emotional intensity during those periods, as well. If you have questions about licensing content on this page, please contact ngimagecollection@natgeo.com for more information and to obtain a license. In the Northern Hemisphere, sun outages occur in the days before the March equinox and after the September equinox. At the time of winter solstice(mid winter in Northern hemisphere, tropic of Capricorn) the sun rays would be 23.5o south of equator(=-23.45o). This makes midsummer in Scandinavia an ideal time for weeklong outdoor music festivals and family vacations. They also correct the 23.44 obliquity which changes very slightly with time. Similarly, approaches zero (at d= 263.75 and 81.25) on both March and September equinoxes. The Rights Holder for media is the person or group credited. National Geographic Headquarters 1145 17th Street NW Washington, DC 20036. They are referred to the equinoxes instead so use sin instead of cos. To find the declination of the sun for a specific date, you need to use an analemma and know the latitude of the location. The Burning of the Socks signifies the warmer, sock-less spring season. She or he will best know the preferred format. In the equation above, the +10 comes from the fact that the winter solstice occurs before the start of the year. It then rises as far south of east and sets as far south of west as possible. Surya Grahan 2023: Impact On Aries (March 21 - April 19) As the first sign of the zodiac, Aries is known for its assertive and confident nature. During Saturn's equinoxes, the rings (and Saturn's equator) line up perfectly with the sun. This is the December solstice. (The only times of the year when the intensity of the suns rays is not unequal are the appropriately named equinoxes. The equation also assumes that the suns orbit is a perfect circle and the factor of 360/365 converts the day number to a position in the orbit. . Solstices are known as midwinter and midsummer for this reason. This is usually done even when the analemma is marked on a geographical globe, on which the continents, etc., are shown with west to the left. To make things simple, we will assume you live in the US or a country from the northern hemisphere. See how this eclipse looks in your city. sun reaches zenith at Noon on two dates between Divide 360 by the number of days in the year. Ancient European tribes celebrated midsummer with feasts and bonfires, intended to drive away evil spirits. Caricorn on the Spring Equinox. //-->, * Exdek = Extreme declinations of latitudes beyond 23 degrees 27 minutes (2327'). The declination angle is negative from September 22nd (Autumnal equinox) to March 20th (spring equinox). In addition to the annual northsouth oscillation of the Sun's apparent position, corresponding to the variation of its declination described above, there is also a smaller but more complex oscillation in the eastwest direction. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. You do not need coordinates to find the solar declination angle since it is independent of the location. 1. Solar declination angle is very useful in calculating the sun elevation and the azimuth angle. The range of solar declination is equal to the Earths obliquity. Winter weather put ancient cultures at their most vulnerable; both food and shelter were limited. The number 10, in (N+10), is the approximate number of days after the December solstice to January 1. Why is it summer in the Northern Hemisphere in June? Earth Sciences questions and answers. One of the most famous expressions of this romantic sentiment is the comic play A Midsummer Nights Dream, by the English writer William Shakespeare. The previous formula is the simplification of the below equation. On these days, the earths axis of rotation becomes perpendicular to the rays of the sun. The declination is zero at the equinoxes (March 22 and September 22), positive during the northern hemisphere summer and negative during the northern hemisphere winter. raw a declination circle with just a ruler and protractor/compass to quickly and accurately know the Suns position in the sky at any day and time of the year for any location on Earth. Click on the following toggles to view descriptions and links of the web pages on each topic of the Sun-Earth Connection. The solar declination (subpolar point) on June 21st is June . The Sun appears to move northward during the northern spring, crossing the celestial equator on the March equinox.Its declination reaches a maximum equal to the angle of Earth's axial tilt (23.44) on the June solstice, then decreases until reaching its minimum (23.44) on the December solstice, when its value is the negative of the axial tilt.. On December 31st (UTC 00:00:00), d = 364. Our goal is to make science relevant and fun for everyone. The author is an engineer, a solar energy enthusiast, and a strong supporter of renewable energy. Although the rings extend thousands of kilometers into space, they are actually very thin, only about a kilometer wide. Because of that, the tilt angle of solar panels increases, and the solar panels are placed almost vertical to maximize solar power. Songpyeon symbolize important elements of Chuseok. The table below lists some examples. After the March equinox, the subsolar point migrates north as the Northern Hemisphere tilts toward the sun. (approx. Zhang, T., Stackhouse, P.W., Macpherson, B., and Mikovitz, J.C., 2021. The value of is maximum (23.44) when the cosine is equal to the negative one. View the astronomical seasons (solstices and equinoxes) and the solar declination, Compare the degree of illumination between the Northern and Southern Hemispheres, and. The equation above gives a rough estimation of the value of solar declination on a particular day, where N is the number of days which have elapsed since 00:01am on 1st January - i.e. Atmospheric refraction is a result of increasing air density, which decreases the velocity of light through the air. This December solstice is called the winter solstice in the northern hemisphere, whereas in the southern, it is the summer solstice. Mars, our other close neighbor, has an axial tilt similar to Earth (24). Most planets experience equinoxes. Since the Earth is tilted on its axis and rotates every year, the angle of declination changes throughout the year. Midnight sun describes the phenomenon surrounding the summer solstice, when the sun remains visible at midnight in the weeks leading up to and following the event. Annapolis, Maryland, celebrates The Burning of the Socks every March equinox. "El Castillo" is a temple honoring the serpent god Kukulcan.Archaeologists and anthropologists have not determined if this phenomenon was intentional or a happy accident. Thus, we can conclude, the maximum value of the solar declination angle is 23.44, and the minimum is 23.44. Not all planets transit into the extreme declinations. the days part of the ordinal date 1) and can include decimals to adjust for local times later or earlier in the day. Saturnalia was celebrated the weeks leading up to the actual solstice. 23.5 deg. Photos taken from the solar perspective reveal the rings as a razor-thin line. Many communications satellites orbit around the Equator, and consumers may experience slow Internet connections, radio static, or frozen television screens during equinoctial sun outages. is my husband a narcissist or am i crazy, okta racetrac login, 16x16 oven rack,