"Green sabres" - how easy is it to identify green satellite trails, from PhotoObj parameter values?

• by JeanTate

  We've all seen them; here's one from a recent comment ( AGZ0002ddj, SDSS J150230.36+290053.1):

  

  How easy is it to identify candidate green satellite trails, from a subset of the PhotoObj parameter values?

  My guess is that it is pretty straight-forward.

  For example, just by eyeballing the image, this "GALAXY" is very bright in the r-band (mapped to G in the RGB JPEG), and likely extremely faint in the g (mapped to B ) and i (R). And so it is; here are the five values, including estimated errors (u, g, r, i, z): (25.28±4.89, 23.86±2.49, 13.44±0.0, 25.94±2.37, 22.48±4.69).

  Ignoring errors, the u, g, i, and z band magnitudes are ~the same as a piece of blank sky*, and the r-band one ~10 mags brighter than the sky*. That's a flux ratio of ~10,000 😮

  As a first pass, how about this (pseudo-code)?

  The SDSS GALAXY is a 'green sabre' candidate IF:

  • g band mag < 21 AND
  • i band mag < 21 AND
  • g-r color > 5 AND
  • i-r color > 5

  Next: grab a few other green sabres and see if the 1st-pass pseudo-code identifies them as candidates.

  What do you think?

  *actually, the sky may well be brighter than ~23 mag; SDSS photometry can reliably go deeper than the sky

  Posted July 27, 2014 2:39 AM

• by JeanTate

  Another: AGZ0002hx5, SDSS J223333.79-001627.9:

  

  (u, g, r, i, z): (25.95±1.46, 24.23±1.42, 14.45±0.00, 22.91±1.09, 24.27±1.09)

  Using the multi-component criterion above, is this a 'green sabre' candidate?

  Yes.

  Posted July 27, 2014 11:37 PM

• by klmasters scientist, admin

  Jean,
  It's a great idea. I'd want to know how many galaxies end up in that compared to the satellite trails.

  You could actually do the search here: http://skyserver.sdss3.org/public/en/tools/search/sql.aspx

  And take a look at the output.

  Karen.

  Posted July 28, 2014 1:50 PM

• by JeanTate in response to klmasters's comment.

  Thanks Karen! 😃

  Posted July 28, 2014 3:05 PM

• by JeanTate in response to klmasters's comment.

  Before I do a search, one more: AGZ0002c6p, SDSS J124622.01+103405.8:

  

  (u, g, r, i, z): (24.91±1.46, 24.98±1.15, 15.03±0.00, 24.19±1.23, 22.81±1.05)

  Using the multi-component criterion above, is this a 'green sabre' candidate?

  Yes.

  Posted July 28, 2014 3:08 PM

• by c_cld

  Sampling SQL Query to put in http://skyserver.sdss3.org/public/en/tools/chart/sqltoform.aspx:
  Your SQL command was:
  SELECT TOP 500
  objid as name, ra, dec
  FROM Photoobj
  WHERE
  insidemask = 4
  and type = 3
  and petroRad_r > 60
  and u > 23
  and g > 23
  and r < 15
  and i > 23
  and z > 22
  order by ra, dec

  Sample:

  name ra dec
  1237678601306439781 2.87045398115032 17.3576949106606
  1237678601306439782 2.90405830489465 17.3503549746631
  1237678601306439798 2.91702256777774 17.3466384801896
  1237678601306505269 3.06564124212548 17.3130909073568
  1237679436133171406 9.36976262906504 -1.56228192317943
  1237679435596759152 10.4667777388803 -2.02486218735909
  1237680121711099942 10.5939116852239 -7.59056226476431
  1237652947993362483 10.6345039496051 -9.70271837358519
  1237680121711165463 10.6945202049163 -7.5112125452461
  1237652947993493539 10.8745483390153 -9.65935660836134
  1237652947993493510 10.9269409203403 -9.64979217886045
  1237652947993690147 11.4236473616581 -9.55943431131731
  1237652947993755735 11.5088184494409 -9.5439553495525
  1237679324462710881 13.8639425179891 -3.93167302786811
  1237679324462710909 13.8842393114591 -3.91970433654689
  1237652629642936431 17.3458487217608 -10.081546757784
  1237649918430609538 19.0476942026643 13.3867369285778
  1237666216231698769 21.3299693849607 46.9654423386144
  1237673700734861435 24.3932794619061 -19.3823918574827
  1237680286534795572 25.9177923350326 29.4326920989027
  1237676673389232304 30.1590235791275 -13.888169615156
  1237679339493458013 31.3792545912185 -7.25237364740833
  1237666408456847805 32.9350592618297 0.416361700089986
  1237679253061042299 34.8819562501399 -5.34162090442424
  1237679253061173289 35.2014765671182 -5.26684136704361
  1237678437551308965 35.3260148090646 1.64361082417567
  1237667227150385198 35.8691524989081 5.25952523866557
  1237678879964856359 41.128231883807 -2.50636770869396
  1237673700207427717 41.2118134933635 -5.3844518331505
  1237673700207558772 41.4773489723061 -5.34929012476385
  1237661055283037413 52.8904469502183 39.6652557437357
  1237645943979376681 57.3838997094222 0.982189043725163
  1237664088065966370 59.3194405956535 17.2707318989029
  1237664088065966328 59.3665699653111 17.2786529740097
  1237664088066097335 59.6918828901756 17.3328666736181
  1237673284129783964 60.1961157497467 14.7110450643572
  1237674286460305664 67.4064885773548 -6.63701657515181
  1237674286460371082 67.4880355845014 -6.67810186782999
  1237673328156410196 68.6612911853664 20.864455851656
  1237674285924810935 70.3756495008 -5.63227553798304
  1237673474178417178 72.0642258598105 12.239199483242
  1237674284852510860 73.6670243815842 -4.86277405624799
  1237673807572173050 101.88420378211 9.90445994918457
  1237667205676335470 102.996699624437 64.6654246713521
  1237667205676335468 103.091925194671 64.6347091550072
  1237673758187257873 105.007099946109 30.6837887049353
  1237673705577775194 113.790193607596 41.1545856580527
  1237673311502532870 114.401439760847 42.1954860042743
  1237673311502598237 114.414373182017 42.3091220725436
  1237651274031562928 120.357542742957 47.5488625817372
  1237673709323223685 121.135408162978 -8.59982314455286
  1237667730731696164 123.343920076294 10.968383263387
  1237667730195152915 124.237857556915 10.9194371834981
  1237667730195152962 124.268092814748 10.9177008772435
  1237653622299230407 126.819953694645 1.40579203923705
  1237674459871511008 126.867992217202 -6.00384732734814
  1237653622836166789 126.877148449604 1.79359644634442
  1237674459871510992 126.909572287924 -6.02299019993793
  1237653622836363551 127.374629984109 1.87686881274859
  1237673807584559229 128.954859615595 21.1198683603553
  1237663916809060457 135.905288439764 63.6942953718866
  1237660412113387556 138.666674180378 6.77550338458892
  1237660344470995080 138.757980838511 37.6339332920967
  1237660344471060613 138.807478723341 37.674527524967
  1237655107292102692 139.292684160892 49.5408802714111
  1237674462027972715 143.53567129798 5.92118853154274
  1237667113334276509 143.695455039025 26.2240034614874
  1237667112797339750 143.783428163207 25.7344558797225
  1237657633799930146 145.076102351341 50.3719096783982
  1237657633799995506 145.094759541838 50.4608147059304
  1237657633799995511 145.101306399559 50.4917481024
  1237654872680235225 146.517791422254 -1.27287150662285
  1237664668433186981 150.00647476447 34.2925041889711
  1237667212664569943 153.021793208711 26.9976389580066
  1237664104706343017 153.449349280919 12.0037169980933
  1237667212128092181 154.128016771942 26.8058307075839
  1237664105243541606 154.191617305795 12.3864926396701
  1237664105243607170 154.32678691855 12.4553805892991
  1237670964854915348 154.729471856064 17.1492941123601
  1237670964854980618 154.744680047894 17.1968768040894
  1237670964854980622 154.755704780071 17.2315044579699
  1237667211591483580 154.780585969645 26.6873015953787
  1237657220947837035 156.225979798104 53.6800499281737
  1237657220947837028 156.290674740332 53.7366473077919
  1237658613589409843 161.68128924538 48.1835185257349
  1237667212668829886 163.73549782557 29.137908983355
  1237668289624604877 164.92574762758 19.1350708161384
  1237668494703722619 165.45566368815 15.7384384599269
  1237661968498163928 167.36156522789 42.1296608389627
  1237658802571182310 170.427816663031 54.67345506023
  1237661068184912107 174.278667878674 13.5648672677471
  1237671139870703773 177.443263725457 0.0966431911625735
  1237661069799587919 183.798475643896 15.1841512399303
  1237658609292869723 183.928789791004 59.2436465045715
  1237667323794424063 186.367729791926 27.9207399574215
  1237671765323808961 190.422448690677 0.931847039252255
  1237664294755762257 191.747846559778 39.6641137091897
  1237671763172917295 191.774064682883 -7.02932338411412
  1237662302967890198 202.011486853351 52.077706139178
  1237662302967955584 202.198949530673 52.0014494949471
  1237655463772487771 202.660820146049 60.6906816214941
  1237655463772487801 202.849742120156 60.5122330165431
  1237648703512707179 204.765551376743 -0.72718243705427
  1237662530063106183 207.03230569098 14.0691095388437
  1237661874021728320 208.972534180834 43.3989481583329
  1237655742402593110 212.011676590018 5.50172109648455
  1237671992959303893 213.213442277126 -13.2361561392393
  1237655744550731839 213.537576635478 7.06044738537057
  1237655744013926557 213.657777709649 6.7819172893327
  1237655744013926559 213.677844682151 6.73564035453081
  1237655744013926553 213.69004419033 6.70739758378498
  1237665532249571341 216.013570406517 24.3696065062857
  1237665532249571374 216.034996623823 24.2984147464912
  1237662267532116090 216.217259822978 6.41625471088578
  1237662267532116086 216.248694240752 6.39301660239087
  1237665567145132247 217.689193554499 22.1989298269547
  1237668349211312378 218.663784278242 14.3213194803612
  1237668349211312345 218.742089808029 14.3551073905886
  1237668349211312318 218.757662547409 14.3617797830041
  1237668272442638534 219.842347515021 16.9911587145019
  1237655371443339561 220.821768575813 58.6853402616251
  1237662637441155109 221.644659436741 12.3650427279996
  1237662695958118585 225.591499849453 29.0678044985638
  1237662695958118670 225.616938096773 29.0292994034918
  1237662695958183963 225.626503642796 29.0147608959847
  1237662695958183975 225.642367744093 28.9909059327637
  1237665549431078971 225.824641100157 21.5195767487175
  1237662661601525835 228.257697461647 30.2994056389144
  1237665532795158655 236.595967702741 18.784694953774
  1237665532795158665 236.662397040203 18.7924892366712
  1237662500542480624 238.671911936432 38.2331300396539
  1237665547826888866 239.940824975287 15.4423300850255
  1237665429184708970 245.852464847087 16.0240518332057
  1237659163887403249 246.429887002374 38.4214333278741
  1237662662146588949 246.547948283234 21.2321004768697
  1237662198292021481 246.751180439553 5.21330837161099
  1237662340552851614 246.961636521554 23.2674491620489
  1237668598849011859 247.834850034869 -5.31051866458923
  1237659162278232172 248.041931709079 35.0851047461748
  1237668599386144790 248.599356326192 -5.3112934310884
  1237648702995300801 249.294951737733 -1.20719441675117
  1237648702995366082 249.375912101176 -1.23784666787047
  1237671937114570817 254.763885460507 42.0050279930259
  1237671937114570815 254.778666072811 42.0481996952844
  1237661386014327006 258.360535366625 22.599730104058
  1237651249915363701 261.313731898642 25.0702915866929
  1237665582726709286 263.477639468733 30.3983534909231
  1237656528386261036 263.988483548951 50.2723874560515
  1237656562752291039 264.587509930122 59.0662184377676
  1237656562752291088 264.707477943808 59.061643484461
  1237665571988111408 264.762842153952 29.2409814058988
  1237651251528401517 265.34033286781 20.6709785287869
  1237651251528401511 265.341216702438 20.6950886062809
  1237651249920475916 267.019725514878 14.650923481124
  1237668658452957248 273.071738059814 11.8414727050109
  1237668658452957222 273.075495277498 11.8184539265529
  1237663229070147655 279.67637875717 77.9348483786132
  1237652599560994956 311.689223022056 -6.13124434318408
  1237652599563026978 316.389692843256 -6.84300695788675
  1237652599563092302 316.481230954601 -6.78499039857896
  1237680192041714116 319.768796697015 -2.67108483805179
  1237666184550416488 320.897543151243 -5.30820916339986
  1237666184550416513 320.96567664471 -5.30831882616824
  1237678825170927779 324.568375799293 3.92894291078357
  1237678825707864175 324.655525711459 4.27935629091583
  1237679997155999864 330.674366202374 -2.45300317246692
  1237679997156065490 330.711646682965 -2.43645877413674
  1237680297807511772 334.548782605743 19.2312240178907
  1237680297807511773 334.570601339362 19.2634829236026
  1237680297807577395 334.611464253056 19.3238719148933
  1237679998231838755 335.399012076252 -1.61414877251031
  1237678600760918134 342.252435970322 15.619959304994
  1237678600760918092 342.265426831035 15.6450597775935
  1237678600760918082 342.326295326534 15.718517213676
  1237678600760918076 342.345807493704 15.7356466194072
  1237679455459475515 354.029678009483 16.4930667440825
  1237679503242821663 354.313319575068 19.3452131815164
  1237679503242821714 354.344545893149 19.3048860097961
  1237679503242821696 354.365833099702 19.2782263584748
  1237679504854024238 355.795186970094 20.7011722452831
  1237679504854089860 355.818886044986 20.6606715480676
  1237679476395999342 358.68105742312 21.5130640156942
  1237679476395999302 358.715473380372 21.4635286783385
  1237678860082151567 359.808941279712 13.2463742444256
  1237679478544007250 359.91327403551 23.1306724839983

  Posted July 29, 2014 2:55 PM

• by c_cld

  green Meteor:

  http://skyserver.sdss3.org/public/en/tools/explore/summary.aspx?id=1237662980496753418

  😃

  http://skyservice.pha.jhu.edu/DR9/ImgCutout/getjpegcodec.aspx?R=4076&C=3&F=41&Z=50

  

  Posted July 29, 2014 3:17 PM

• by c_cld

  Formation of three satellites in equatorial orbit:

  http://skyservice.pha.jhu.edu/DR10/ImgCutout/getjpeg.aspx?ra=41.3068980880766&dec=-5.34174615518778&scale=1.584508&width=990&height=640&opt=&query=

  

  Other equatorial formation:
  http://skyservice.pha.jhu.edu/DR10/ImgCutout/getjpeg.aspx?ra=249.05&dec=-5.31051866458923&scale=6.338032&width=990&height=512&opt=&query=

  

  Posted July 29, 2014 3:33 PM

• by c_cld

  AGZ0001tie equatorial trail orbit

  1237654670276952292

  zoom-out

  

  1237654670277279817

  Posted July 29, 2014 9:47 PM

• by ElisabethB moderator

  You can still post in this thread. You need to refresh to see your new post.
  We are not sure what happened, but we are looking into it.

  Posted July 30, 2014 8:24 AM

• by c_cld

  AGZ0001tie equatorial trail orbit

  possible identification as geosynchronous satellite Galaxy-27 (G-27, Intelsat IA-7, Telstar 7) located at longitude -128.93 launched on 25/9/1999

  Perigee (km) Apogee (km) Inclination (degrees) Period (minutes)

  35,776 35,794 0 1436.06

  Posted July 30, 2014 3:52 PM

• by c_cld

  Looking at the frame http://dr10.sdss3.org/sas/dr10/boss/photoObj/frames/301/2141/4/frame-irg-002141-4-0124.jpg

  

  at middle up you could see asteroid 1237654670277345418

  69757 (1998 OD7)

  Classification: Main-belt Asteroid SPK-ID: 2069757 earth distance 1.579AU

  

  It's a perfect illustration of angular velocity on asteroid main belt orbit and satellite geosynchronous orbit seen from Apache observatory 😃

  Another faint asteroid is displayed on adjacent frame near spiral PGC32088.

  Posted July 30, 2014 4:13 PM

• by zutopian

  vrooje did following post in another discussion on 4 July 2014.:

  Ooh, that's a good one to use as a test on the satellite trail finder program we've been working on (so that we can try to mark these in Talk and elsewhere). It's nice and faint so it will be a challenge for the algorithm. Thank you!

  http://talk.galaxyzoo.org/#/boards/BGZ0000005/discussions/DGZ0000ux9

  Posted July 31, 2014 12:50 AM

• by zutopian

  In a GZ tweet* they informed about following blog post by the computer engineer Matthew Sottile.:

  Satellite trail identification in GalaxyZoo images Posted on November 6, 2014
  http://syntacticsalt.com/2014/11/06/satellite-trail-identification-in-galaxyzoo-images/

  '* https://twitter.com/galaxyzoo/status/530361537337102336

  Posted November 15, 2014 10:08 AM

• by JeanTate in response to zutopian's comment.

  Interesting! 😃

  I wonder why "Comments are closed."? It would seem to be a topic on which comments would be welcomed, wouldn't it?

  Posted November 15, 2014 10:22 AM

• by Budgieye moderator in response to C_cld's comment.

  I think this one is a flash of sunlight from a satellite. see Forum: Sunday 12th August 2012: What's this then? by Alice http://www.galaxyzooforum.org/index.php?topic=280334.msg612835#msg612835

  Posted November 15, 2014 7:32 PM

• by c_cld

  2000-05-05 07:23:11.790 UTC sequential frames of satellite trail (rig filters mapped to GRB channels)

  

  zoomed in

  reflected light by opposite solar panels across spacecraft?

  Posted December 1, 2014 2:49 PM

• by c_cld

  Flaring satellite http://dr10.sdss3.org/fields/runCamcolField?run=4623&camcol=1&field=140

  

  Posted January 5, 2015 4:33 PM

• by c_cld

  Flashing satellite in green filter

  http://dr12.sdss3.org/sas/dr12/boss/photoObj/frames/301/4208/1/frame-irg-004208-1-0170.jpg

  http://dr12.sdss3.org/sas/dr12/boss/photoObj/frames/301/4208/1/frame-irg-004208-1-0171.jpg

  http://dr12.sdss3.org/sas/dr12/boss/photoObj/frames/301/4208/1/frame-irg-004208-1-0172.jpg

  http://dr12.sdss3.org/sas/dr12/boss/photoObj/frames/301/4208/1/frame-irg-004208-1-0173.jpg

  and in red filter

  http://dr12.sdss3.org/sas/dr12/boss/photoObj/frames/301/4208/1/frame-irg-004208-1-0167.jpg

  

  

  Posted January 15, 2015 9:04 AM