Skip to main content
JSON Notices via Email, Kafka Cron Jobs, Submitter Profile, GCN is Hiring. See news and announcements

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_MC161217_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').
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"

10956 results found.

  1. GRB 251013C: ALMA detection
  2. GRB 251013C: SAO RAS optical observations
  3. GRB 251013C: SVOM detection of a burst
  4. GRB 251003A: Mondy optical upper limit
  5. MASTER OT J011025.98-583210.6 : SVOM/VT optical observation
  6. GRB 251011B inspection: MASTER orphan GRB detection
  7. GRB 251011B : MASTER optical observations
  8. GRB 251011B: Swift detection of a burst
  9. GRB 251006A: CALET Gamma-Ray Burst Monitor detection
  10. GRB 251007B - SVOM/ECLAIRs refined analysis
  11. GRB 251002A - SVOM/ECLAIRs refined analysis
  12. EP250911a: Koshka Zeiss-1000 Optical Upper Limit
  13. GRB 251007B: SVOM/VT optical candidate
  14. GRB 251007A: CALET Gamma-Ray Burst Monitor detection
  15. GRB 251005C: PRIME J-band upper limit
  16. GRB 251007B: SVOM/C-GFT upper limit
  17. GRB 251007B: SVOM detection of a faint burst
  18. GRB 251007B: Swift detection of a burst
  19. GRB 251007A: Swift detection of a burst with an optical counterpart
  20. GRB 251005C: SVOM/VT optical fading
  21. GRB 251005C: SVOM/VT optical candidate
  22. GRB 251005C: Swift/UVOT Upper Limits
  23. GRB 250902A: MSU cubesats detection
  24. GRB 251005C: Swift detection of a burst
  25. GRB 251002A: Mondy/AZT-33IK optical observations
  26. GRB 251001B: AbAO optical upper limit
  27. GRB 251002A: AbAO optical observations
  28. GRB 251001C: CALET Gamma-Ray Burst Monitor detection
  29. GRB 251002A: J band observations by SYSU 80cm infrared telescope
  30. GRB 251002A: OHP/T193 MISTRAL optical afterglow detection
  31. GRB 251002A: VLT/X-shooter spectroscopic redshift z = 2.178
  32. GRB 251002A: SVOM detection of a burst
  33. GRB 251001B: SVOM/VT optical observation
  34. GRB 250910A / EP250910a: VLT limits on the possible associated supernova
  35. LIGO/Virgo/KAGRA S250818k: further MeerKAT monitoring
  36. GRB 250910A / EP250910a: VLT/X-shooter host galaxy redshift z = 0.592
  37. GRB 250926A: CALET Gamma-Ray Burst Monitor detection
  38. GRB 250925A: Mondy I-band optical observations
  39. GRB 250916A: SVOM/VT optical observation
  40. GRB 250925A: Swift/UVOT Upper Limits
  41. GRB 250925A: Mondy and AbAO optical observations
  42. GRB 250925A: COLIBRÍ photometric redshift
  43. GRB 250925A : MITSuME Akeno optical upper limits
  44. GRB 250925A: COLIBRÍ optical photometry of the afterglow
  45. GRB 250925A: Swift detection of a burst
  46. GRB 250924A: SAO RAS optical observations
  47. GRB 250924A: SVOM/VT optical observation
  48. GRB 250924A: Mondy optical observations, afterglow fading
  49. GRB 250920B: AbAO optical upper limits
  50. GRB 250920C: VLT redshift confirmation z = 1.399
  51. GRB 250920B: CrAO ZTSH optical observations
  52. GRB 250920B: SAO RAS optical observations
  53. GRB 250920C: PRIME near-infrared detection
  54. GRB 250916A: CrAO ZTSh R-band optical observations
  55. GRB 250916A: SAO RAS Zeiss-1000 optical observations
  56. GRB 250920B: Kitab-ISON optical upper limit
  57. GRB 250917B: Mondy and Zeiss-1000 SAO RAS optical observations, optical observations, afterglow candidate
  58. GRB 250920C: Swift/UVOT Detection
  59. GRB 250920C: Swift detection of a burst
  60. LIGO/Virgo/KAGRA S250920bq: Coverage and upper limits from MAXI/GSC observations
  61. GRB 250920B: Swift detection of a burst with a bright optical counterpart.
  62. GRB 250919A/EP250919a: SVOM/VT optical observation
  63. GRB 250916A: Mondy R-band optical observations
  64. GRB 250919A: Fermi-LAT detection
  65. EP250919a/GRB 250919A: Gemini/GMOS-S spectroscopic redshift z = 1.145
  66. GRB 250916A: further SAO RAS optical observations
  67. GRB 250916A: OSIRIS+/GTC redshift z = 2.015
  68. SVOM/sb25091517: Confirmation of a stellar flare by SVOM/VT
  69. GRB 250912A: SVOM/COLIBRÍ (FM-GFT) optical observations
  70. GRB 250912A: VLT observations
  71. GRB 250912A:SVOM/VT optical upper limit
  72. EP250908c: tentative VLT/FORS2 redshift z = 2.87
  73. GRB 250911A: Swift-BAT refined analysis
  74. EP250911a: SVOM/VT optical observation
  75. EP250911a: Optical detection with Kinder observations
  76. GRB 250911A: Swift/UVOT Detection
  77. GRB 250911A: Swift detection of a burst
  78. EP250910a/GRB 250910A: EP-WXT detection of a fast X-ray transient
  79. GRB 250910A: SVOM/VT optical upper limit
  80. GRB 250910A: LCO optical upper limit
  81. GRB 250702B: Late time Chandra observations
  82. GRB 250907A: CALET Gamma-Ray Burst Monitor detection
  83. EP250908c: SVOM/VT optical observation
  84. EP250908b: SVOM/VT optical candidate (Coordinate supplement for GCN 41758)
  85. EP250908b: SVOM/VT optical candidate
  86. SVOM/sb25090605: detection of an X-ray transient from the LMXB 4U 0513-40
  87. LIGO/Virgo/KAGRA S250830bp: DECam DESGW Epoch 2 Candidates
  88. EP250905a: Liverpool Telescope observations
  89. GRB 250902B: CALET Gamma-Ray Burst Monitor detection
  90. EP250827b: Gemini Spectroscopic Confirmation of AT2025wkm as a Ic-BL Supernova
  91. GRB 250904A: Swift detection of a burst
  92. GRB 250902A: CALET Gamma-Ray Burst Monitor detection
  93. GRB 250902A: VZLUSAT-2 detection
  94. EP250903a: retraction of the LCO candidate, and discovery of the likely counterpart
  95. EP-WXT trigger 01709201209: Liverpool Telescope upper limits
  96. GRB 250830C: VZLUSAT-2 detection
  97. GRB 250903A: VLT X-shooter spectroscopic redshift z = 1.590
  98. EP250903a: SVOM/VT optical confirmation
  99. EP250827b: SVOM/VT observation of AT 2025wkm
  100. GRB 250831A (SVOM trigger sb25083102): confirmation of a stellar flare by SVOM/VT

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov