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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21987 results found.

  1. GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst
  2. ZTF23aaoohpy/AT2023lcr : HCT follow-up observations
  3. Fermi GRB 230707A: Global MASTER-Net observations report
  4. Integral GRB230706.70: Global MASTER-Net observations report
  5. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  6. ZTF23aaoohpy/AT2023lcr: AMI-LA radio detection
  7. Fermi trigger No 710117592: Global MASTER-Net observations report
  8. GRB 230328B: LBT detection of the likely host galaxy
  9. LIGO/Virgo/KAGRA S230627c: observations of ZTF23aaptsuy/AT2023lx in AbAO observatory
  10. GRB 230628E: Swift/UVOT Detection
  11. GRB 230628E: ATCA rapid radio follow-up
  12. LIGO/Virgo/KAGRA S230627c: GRANDMA observations of galaxies and ZTF counterpart candidates
  13. LIGO/Virgo/KAGRA S230627c: Upper limits from Swift/BAT-GUANO
  14. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  15. GRB 230628E - VLT spectroscopic observations
  16. ZTF23aaoohpy/AT2023lcr: LBT observations
  17. Fermi GRB 230628C: Global MASTER-Net observations report
  18. GRB230628E: VLT optical identification of afterglow candidate
  19. Fermi GRB 230628D: Global MASTER-Net observations report
  20. Swift GRB230628.93: Global MASTER-Net observations report
  21. GRB 230628B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  22. LIGO/Virgo/KAGRA S230516az: GOTO candidate counterpart GOTO23hu ruled out by Zwicky Transient Facility observations
  23. LIGO/Virgo/KAGRA S230627c: Additional observations from the Zwicky Transient Facility
  24. AT2023lcr: JCMT SCUBA-2 sub-mm observations
  25. LIGO/Virgo/KAGRA S230627c: ATLAS information on the ZTF candidates
  26. LIGO/Virgo/KAGRA S230627c: Upper limits from Fermi-GBM Observations
  27. LIGO/Virgo/KAGRA S230627c: Global MASTER-Net observations report
  28. LIGO/Virgo/Kagra S230627c: NED Galaxies in the Localization Volume
  29. LIGO/Virgo/KAGRA S230627c: Zwicky Transient Facility observations and candidates
  30. LIGO/Virgo/KAGRA S230627c: Coverage and upper limits from MAXI/GSC observations
  31. GRB 230625B: Swift/BAT-GUANO detection of a long burst
  32. GRB 230623A: Swift-XRT observations
  33. INTEGRAL upper limit on any GRB associated with ZTF23aaoohpy/AT2023lcr
  34. ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
  35. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  36. GRB 230623B: Swift/BAT-GUANO detection of a long burst outside the coded FOV 
  37. GRB 230623A: Tiled Swift observations
  38. MAXI GRB 230623A: MASTER optical observations
  39. GRB 230623A: Tiled Swift observations
  40. GRB 230622A: ATCA rapid radio follow-up
  41. Swift GRB 230622A: Global MASTER-Net observations report
  42. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic classification of GOTO23hn
  43. LIGO/Virgo S230622e: Global MASTER-Net observations report
  44. LIGO/Virgo S230621bq: Global MASTER-Net observations report
  45. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  46. LIGO/Virgo/KAGRA S230615az: LBT spectroscopic redshift of the host galaxy of GOTO23hn
  47. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  48. Fermi trigger No 709083929: Global MASTER-Net observations report
  49. Fermi GBM-230619: A soft subthreshold candidate potentially associated with a subthreshold LIGO/Virgo compact binary merger candidate
  50. AT2023lcr: VLA radio detection
  51. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  52. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Upper limits from Konus-Wind observations
  53. LIGO/Virgo S230620ad: Global MASTER-Net observations report
  54. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  55. LIGO/Virgo S230620au: Global MASTER-Net observations report
  56. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  57. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  58. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): Kinder observations with Lulin observatory and a probable plateau in the g-band light curve
  59. AT2023lcr: Pan-STARRS & ATLAS Observations
  60. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  61. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  62. LIGO/Virgo/KAGRA S230615az: Wendelstein observations of DESI galaxies and GIT candidates
  63. LIGO/Virgo S230620al: Global MASTER-Net observations report
  64. LIGO/Virgo S230620af: Global MASTER-Net observations report
  65. LIGO/Virgo S230620z: Global MASTER-Net observations report
  66. LIGO/Virgo S230620w: Global MASTER-Net observations report
  67. LIGO/Virgo S230619bg: Global MASTER-Net observations report
  68. LIGO/Virgo S230620g: Global MASTER-Net observations report
  69. LIGO/Virgo S230619ay: Global MASTER-Net observations report
  70. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  71. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations
  72. LIGO/Virgo S230619bd: Global MASTER-Net observations report
  73. LIGO/Virgo S230619bb: Global MASTER-Net observations report
  74. LIGO/Virgo S230619as: Global MASTER-Net observations report
  75. LIGO/Virgo S230619ap: Global MASTER-Net observations report
  76. ZTF23aaoohpy/AT2023lcr: GROWTH-India Telescope follow-up observations
  77. GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
  78. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  79. ZTF23aaoohpy/AT2023lcr: Zwicky Transient Facility discovery of a fast fading red transient
  80. LIGO/Virgo S230619i: Global MASTER-Net observations report
  81. LIGO/Virgo/KAGRA S230615az: GRANDMA observations of GOTO and GIT candidates
  82. LIGO/Virgo S230619aa: Global MASTER-Net observations report
  83. LIGO/Virgo S230619x: Global MASTER-Net observations report
  84. LIGO/Virgo S230619e: Global MASTER-Net observations report
  85. LIGO/Virgo S230618at: Global MASTER-Net observations report
  86. LIGO/Virgo S230618ba: Global MASTER-Net observations report
  87. LIGO/Virgo S230618az: Global MASTER-Net observations report
  88. LIGO/Virgo S230618ae: Global MASTER-Net observations report
  89. LIGO/Virgo S230618aq: Global MASTER-Net observations report
  90. LIGO/Virgo S230618y: Global MASTER-Net observations report
  91. LIGO/Virgo S230618s: Global MASTER-Net observations report
  92. GRB 230618A: Swift/UVOT Upper Limits
  93. GRB 230616A: Swift-XRT observations
  94. LIGO/Virgo S230618r: Global MASTER-Net observations report
  95. LIGO/Virgo S230616aa: Global MASTER-Net observations report
  96. LIGO/Virgo S230615an: Global MASTER-Net observations report
  97. LIGO/Virgo S230615ak: Global MASTER-Net observations report
  98. GRB 230618A: KAIT Optical Observations
  99. LIGO/Virgo S230617ba: Global MASTER-Net observations report
  100. LIGO/Virgo S230618k: Global MASTER-Net observations report

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