# Use of the UGRIZY filters in the search for periodic signals **URL:** \ **Category:** Support\ **Created:** [November 5, 2024, 11:32pm UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529 "2024-11-05T23:32:51Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![sdcorle1](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/sdcorle1/32/3052_2.png) [@sdcorle1](https://www.rubin.community/u/sdcorle1)\ **Post date:** [November 5, 2024, 11:32pm UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/1 "2024-11-05T23:32:51Z")
I am running a custom notebook in DP0 that searches for periodic signals in the Object table. In one case, I see a very wide separation between the results using the U filter and the other 5 filters. A plotted Lomb-Scargle periodogram shows a strong agreement with the 5 filters but my code is blending all 6 filters. The U contribution skews the results away from what the periodogram is suggesting. What document would be a good source of how we should be handling the filters in our research? ---
**Author:** ![ameisner](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/ameisner/32/2392_2.png) [@ameisner](https://www.rubin.community/u/ameisner)\ **Post date:** [November 6, 2024, 2:27am UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/2 "2024-11-06T02:27:46Z")
Hi @sdcorle1 – thanks for your message. Might your notebook be posted anywhere such as GitHub where it’d be possible to have a look at it? My sense is that the appropriate handling of u-band will depend strongly on the science application e.g., u-band will be very important for stellar photometric metallicities but not really relevant for late-type brown dwarfs. To understand how to handle u-band (and the other bands) for a given science application, the key items to consider would be the per-filter [LSST throughput curves](https://github.com/lsst/throughputs/blob/main/baseline/README.md), the LSST per-filter [depths](https://www.lsst.org/scientists/keynumbers), and the anticipated spectral energy distribution of the source(s) of interest. Thanks again. ---
**Author:** ![sdcorle1](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/sdcorle1/32/3052_2.png) [@sdcorle1](https://www.rubin.community/u/sdcorle1)\ **Post date:** [November 6, 2024, 8:17am UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/3 "2024-11-06T08:17:55Z")
Aaron, My notebook is located at notebooks/delegate-contributions-dp03/astrometry/PhotometrySolutionForTransitingPlanets.ipynb and it was adapted from DP02\_07b\_Variable\_Star\_Lightcurves. It is very much a work in progress. Can you access it directly from the Rubin Science Platform? ---
**Author:** ![sdcorle1](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/sdcorle1/32/3052_2.png) [@sdcorle1](https://www.rubin.community/u/sdcorle1)\ **Post date:** [November 6, 2024, 8:20am UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/4 "2024-11-06T08:20:38Z")
The code that I am using is only in section 2.1.2 ---
**Author:** ![sdcorle1](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/sdcorle1/32/3052_2.png) [@sdcorle1](https://www.rubin.community/u/sdcorle1)\ **Post date:** [November 6, 2024, 8:28am UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/5 "2024-11-06T08:28:10Z")
Typically V and B are used for exoplanet research. I see some literature regarding a similar mapping issue with SDSS data which also uses the URGIZY filters. ---
**Author:** ![sdcorle1](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/sdcorle1/32/3052_2.png) [@sdcorle1](https://www.rubin.community/u/sdcorle1)\ **Post date:** [November 6, 2024, 7:41pm UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/6 "2024-11-06T19:41:07Z")
I’m told that ‘g’ is the best band for exoplanet watching. ---
**Author:** ![ameisner](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/ameisner/32/2392_2.png) [@ameisner](https://www.rubin.community/u/ameisner)\ **Post date:** [November 7, 2024, 12:35am UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/7 "2024-11-07T00:35:46Z")
> [@sdcorle1](#): > > notebooks/delegate-contributions-dp03/astrometry/PhotometrySolutionForTransitingPlanets.ipynb If I’ve guessed your RSP user name correctly, then it appears that I don’t currently have read access to your home directory on RSP (I get a `Permission denied` message). If it works with your schedule, you might consider attending tomorrow’s Rubin Science Assembly, which will be open for Q&A (though I personally can’t make it due to a conflicting meeting): > [@Rubin Science Assembly on Thursday November 7th: Q&A with the Rubin CST staff](http://www.rubin.community/t/rubin-science-assembly-on-thursday-november-7th-q-a-with-the-rubin-cst-staff/9530): > > The next Rubin Science Assembly will take place on Thursday, November 7 at 9AM Pacific - you are invited to join! Please note that the US switched to the “Winter time” last weekend. This is another “off-week” event, which will not include any specific presentations - instead, the meeting will be an open drop-in time for Q&A with Rubin staff on-hand to answer any questions you might have. We plan to have some break-out rooms if you would like to co-work with other participants. Zoom connectio… > [@sdcorle1](#): > > I’m told that ‘g’ is the best band for exoplanet watching. I don’t identify as an exoplanet expert, but I would expect this to vary depending on the host star population of interest e.g., TESS is going after nearby cool dwarfs with a relatively red bandpass centered near 800 nm. ---
**Author:** ![ChristinaWilliams](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/christinawilliams/32/2227_2.png) [@ChristinaWilliams](https://www.rubin.community/u/ChristinaWilliams)\ **Post date:** [November 18, 2024, 10:03pm UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/8 "2024-11-18T22:03:17Z")
Hi @sdcorle1, I just wanted to check in to see if your original question was resolved, in case that can help other users with similar questions. If your question is still unresolved can you let us know what might help us get you an answer? Thank you! ---
**Author:** ![sdcorle1](https://sea2.discourse-cdn.com/flex002/user_avatar/www.rubin.community/sdcorle1/32/3052_2.png) [@sdcorle1](https://www.rubin.community/u/sdcorle1)\ **Post date:** [November 19, 2024, 1:56pm UTC](https://www.rubin.community/t/use-of-the-ugrizy-filters-in-the-search-for-periodic-signals/9529/9 "2024-11-19T13:56:56Z")
Christina, yes my question has been resolved. The g band is typically used for exoplanet research. I also noticed that the precision standards for Rubin that were published in 2008 selected the g band values for general distribution when describing Rubin’s precision.