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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.

"N/A_MC151116_R1" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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').
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10931 results found.

  1. GRB 251001B: AbAO optical upper limit
  2. GRB 251002A: AbAO optical observations
  3. GRB 251001C: CALET Gamma-Ray Burst Monitor detection
  4. GRB 251002A: J band observations by SYSU 80cm infrared telescope
  5. GRB 251002A: OHP/T193 MISTRAL optical afterglow detection
  6. GRB 251002A: VLT/X-shooter spectroscopic redshift z = 2.178
  7. GRB 251002A: SVOM detection of a burst
  8. GRB 251001B: SVOM/VT optical observation
  9. GRB 250910A / EP250910a: VLT limits on the possible associated supernova
  10. LIGO/Virgo/KAGRA S250818k: further MeerKAT monitoring
  11. GRB 250910A / EP250910a: VLT/X-shooter host galaxy redshift z = 0.592
  12. GRB 250926A: CALET Gamma-Ray Burst Monitor detection
  13. GRB 250925A: Mondy I-band optical observations
  14. GRB 250916A: SVOM/VT optical observation
  15. GRB 250925A: Swift/UVOT Upper Limits
  16. GRB 250925A: Mondy and AbAO optical observations
  17. GRB 250925A: COLIBRÍ photometric redshift
  18. GRB 250925A : MITSuME Akeno optical upper limits
  19. GRB 250925A: COLIBRÍ optical photometry of the afterglow
  20. GRB 250925A: Swift detection of a burst
  21. GRB 250924A: SAO RAS optical observations
  22. GRB 250924A: SVOM/VT optical observation
  23. GRB 250924A: Mondy optical observations, afterglow fading
  24. GRB 250920B: AbAO optical upper limits
  25. GRB 250920C: VLT redshift confirmation z = 1.399
  26. GRB 250920B: CrAO ZTSH optical observations
  27. GRB 250920B: SAO RAS optical observations
  28. GRB 250920C: PRIME near-infrared detection
  29. GRB 250916A: CrAO ZTSh R-band optical observations
  30. GRB 250916A: SAO RAS Zeiss-1000 optical observations
  31. GRB 250920B: Kitab-ISON optical upper limit
  32. GRB 250917B: Mondy and Zeiss-1000 SAO RAS optical observations, optical observations, afterglow candidate
  33. GRB 250920C: Swift/UVOT Detection
  34. GRB 250920C: Swift detection of a burst
  35. LIGO/Virgo/KAGRA S250920bq: Coverage and upper limits from MAXI/GSC observations
  36. GRB 250920B: Swift detection of a burst with a bright optical counterpart.
  37. GRB 250919A/EP250919a: SVOM/VT optical observation
  38. GRB 250916A: Mondy R-band optical observations
  39. GRB 250919A: Fermi-LAT detection
  40. EP250919a/GRB 250919A: Gemini/GMOS-S spectroscopic redshift z = 1.145
  41. GRB 250916A: further SAO RAS optical observations
  42. GRB 250916A: OSIRIS+/GTC redshift z = 2.015
  43. SVOM/sb25091517: Confirmation of a stellar flare by SVOM/VT
  44. GRB 250912A: SVOM/COLIBRÍ (FM-GFT) optical observations
  45. GRB 250912A: VLT observations
  46. GRB 250912A:SVOM/VT optical upper limit
  47. EP250908c: tentative VLT/FORS2 redshift z = 2.87
  48. GRB 250911A: Swift-BAT refined analysis
  49. EP250911a: SVOM/VT optical observation
  50. EP250911a: Optical detection with Kinder observations
  51. GRB 250911A: Swift/UVOT Detection
  52. GRB 250911A: Swift detection of a burst
  53. EP250910a/GRB 250910A: EP-WXT detection of a fast X-ray transient
  54. GRB 250910A: SVOM/VT optical upper limit
  55. GRB 250910A: LCO optical upper limit
  56. GRB 250702B: Late time Chandra observations
  57. GRB 250907A: CALET Gamma-Ray Burst Monitor detection
  58. EP250908c: SVOM/VT optical observation
  59. EP250908b: SVOM/VT optical candidate (Coordinate supplement for GCN 41758)
  60. EP250908b: SVOM/VT optical candidate
  61. SVOM/sb25090605: detection of an X-ray transient from the LMXB 4U 0513-40
  62. LIGO/Virgo/KAGRA S250830bp: DECam DESGW Epoch 2 Candidates
  63. EP250905a: Liverpool Telescope observations
  64. GRB 250902B: CALET Gamma-Ray Burst Monitor detection
  65. EP250827b: Gemini Spectroscopic Confirmation of AT2025wkm as a Ic-BL Supernova
  66. GRB 250904A: Swift detection of a burst
  67. GRB 250902A: CALET Gamma-Ray Burst Monitor detection
  68. GRB 250902A: VZLUSAT-2 detection
  69. EP250903a: retraction of the LCO candidate, and discovery of the likely counterpart
  70. EP-WXT trigger 01709201209: Liverpool Telescope upper limits
  71. GRB 250830C: VZLUSAT-2 detection
  72. GRB 250903A: VLT X-shooter spectroscopic redshift z = 1.590
  73. EP250903a: SVOM/VT optical confirmation
  74. EP250827b: SVOM/VT observation of AT 2025wkm
  75. GRB 250831A (SVOM trigger sb25083102): confirmation of a stellar flare by SVOM/VT
  76. GRB 250901A: EP-FXT follow-up observation
  77. EP250827b: Gemini Spectroscopy of AT 2025wkm
  78. EP250831a: NOT optical observations and tentative afterglow candidate
  79. LIGO/Virgo/KAGRA S250831cc: Coverage and upper limits from MAXI/GSC observations
  80. LIGO/Virgo/KAGRA S250830bp: Coverage and upper limits from MAXI/GSC observations
  81. EP-WXT trigger 01709200994: Liverpool Telescope upper limits
  82. GRB 250830B: MAXI/GSC detection
  83. GRB 250830A / MAXI J0853+337: MAXI/GSC detection
  84. EP250828a: Optical counterpart detection with Kinder observations
  85. EP250828a: SVOM/VT optical candidate
  86. EP250828a: Optical upper limit with Kinder observations
  87. EP250827A: VLT/X-shooter redshift confirmation
  88. GRB 250806A: HiPERCAM/GTC limits on a possible supernova
  89. LIGO/Virgo/KAGRA S250818k: SAO RAS BTA z-band observations of AT2025ulz
  90. LIGO/Virgo/KAGRA S250818k: MASTER predicovery limits of the AT2025ulz/ZTF25abjmnps KN candidate
  91. GRB 250823A: SVOM/VT optical observation
  92. GRB 250823A: Swift detection of a burst
  93. LIGO/Virgo/KAGRA S250818k: Rebrightening detected with Gemini/GMOS
  94. LIGO/Virgo/KAGRA S250818k: J-GEM follow-up observation for AT2025ulz
  95. LIGO/Virgo/KAGRA S250818k: PRIME nIR observations of AT2025ulz
  96. EP250821a: VLT X-shooter spectroscopic redshift z = 0.577
  97. LIGO/Virgo/KAGRA S250818k: GRAWITA TNG NIR observations of AT2025ulz
  98. EP250821a: SVOM/VT optical observation
  99. GRB 250814A: CMO SAI and SAO RAS izJ observations.
  100. LIGO/Virgo/KAGRA S250818k: WFST pre-discovery limits and follow-up observations of AT 2025ulz

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