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.

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"

37677 results found.

  1. GRB 250114B: SVOM/VT upper limit
  2. Fermi Gamma-ray Burst Monitor trigger 758659047/250115776 is not a GRB
  3. GRB 250101A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations and rebrightening.
  4. Konus-Wind detection of GRB 250113A
  5. IPN triangulation of GRB 250113A
  6. GRB 250114B: Liverpool Telescope optical upper limit
  7. GRB 250114B : MITSuME Akeno optical afterglow candidate detection
  8. GRB 250114B: Swift-XRT observations
  9. GRB 250114A: LCO optical counterpart detection.
  10. GRB 250114B: OHP/T193 optical upper limit
  11. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  12. GRB 250114A: Swift-XRT refined Analysis
  13. GRB 250114A: LCOGT optical afterglow i-band detection
  14. GRB 250114B : GIT optical upper limit
  15. GRB 250114B: Swift ToO observations
  16. EP250111a: SAO RAS optical upper limit
  17. GRB 250114B: a short GRB detected with INTEGRAL
  18. GRB 250114A: Enhanced Swift-XRT position
  19. GRB 250113A: INTEGRAL/SPI-ACS detection
  20. GRB 250114A: VLT/X-shooter spectroscopic redshift z = 4.732
  21. GRB 250114A: REM detection of the optical and NIR counterpart
  22. GRB 250114A: LCO optical observations
  23. GRB 250114A: TRT optical observations
  24. Swift GRB 250114A: Global MASTER-Net observations report
  25. GRB 250114A: Swift detection of a burst with an optical counterpart
  26. GRB 250101A: Terskol Zeiss-2000 optical observations
  27. EP250108a / AT 2025kg: SAO RAS optical observations
  28. GRB 250113A: SVOM/GRM observation of a long burst
  29. GRB 250107A: VZLUSAT-2 detection
  30. GRB 250109A / EP250109a: GRBAlpha detection
  31. GRB 250107D: GRBAlpha detection
  32. GRB 250106A: Swift-XRT afterglow detection
  33. Fermi trigger No 758442826: Global MASTER-Net observations report
  34. EP250111a: KAIT optical observations
  35. GRB 250109A / EP250109a: Mephisto optical upper limits
  36. EP250111a: Mondy optical observation
  37. EP250109a/GRB 250109A:SVOM/VT optical counterpart
  38. GRB 250101B: Fermi GBM Observation
  39. EP250108a: further NOT optical observations
  40. GRB 250109A / EP250109a: Terskol (INASAN) and SAO RAS observations
  41. GRB 250109A / EP250109A: Swift/BAT-GUANO localization skymap of a burst
  42. GRB 250109A / EP250109a: Swift detection of the X-ray afterglow
  43. GRB 250108A: Swift/XRT afterglow fading
  44. GRB 250107D: CALET Gamma-Ray Burst Monitor detection
  45. GRB 250107C: CALET Gamma-Ray Burst Monitor detection
  46. Konus-Wind detection of GRB 250107C
  47. GRB 250101A: CMO RC-500 optical observations
  48. EP250109a / GRB 250109A: refined EP-WXT analysis and EP-FXT follow-up observation
  49. GRB 250109A: Fermi GBM Observation
  50. EP250108a: NOT optical observations
  51. GRB 250109a: GMG Optical Upper Limit
  52. Konus-Wind detection of GRB 250107D (short/hard)
  53. IPN triangulation of GRB 250107D (short/hard)
  54. IPN triangulation of GRB 250107C
  55. GRB 250108B: Gemini-North likely redshift z = 2.197
  56. GRB 250108B: Swift-BAT refined analysis
  57. GRB 250108B: 1.3m DFOT upper limit
  58. GRB 250108B: REM optical/NIR upper limits
  59. GRB 250109A /EP250109a: Fermi GBM Final Localization
  60. GRB 250107C: SVOM/GRM observation
  61. GRB 250101A: Terskol K-800 optical observations
  62. EP250109a: Swift/XRT non-detection
  63. GRB 250108A: Swift/UVOT Upper Limits
  64. GRB 250108A: NOT optical upper limit
  65. GRB 250108B: Swift-XRT refined Analysis
  66. Swift GRB 250108B: Global MASTER-Net observations report
  67. Fermi Gamma-ray Burst Monitor trigger 758061038/250108855 is not a GRB
  68. LIGO/Virgo/KAGRA S250108ha: Retraction of GW compact binary merger candidate
  69. GRB 250108B: Gemini-North Candidate Optical Afterglow Detection
  70. GRB 250103A: 1.6m Mephisto optical observations
  71. GRB 250108A: Swift-XRT afterglow detection
  72. GRB 250108A:SVOM/VT optical candidate
  73. GRB 250108B: Swift/UVOT Upper Limits
  74. GRB 250103A: Swift-XRT afterglow detection
  75. GRB 250108B: Enhanced Swift-XRT position
  76. GRB 250108B: Swift detection of a burst
  77. GRB 250108A: Swift ToO observations
  78. GRB 250108A: SVOM detection of a soft long burst
  79. GRB 250107A: Fermi GBM Observation
  80. GRB 241228B: Fermi-LAT detection
  81. Fermi GRB 250107B: Global MASTER-Net observations report
  82. GRB 250107A: Swift ToO observations
  83. GRB 250107A: Swift/BAT-GUANO arcminute localization of a burst
  84. GRB 250107B: Fermi GBM Final Real-time Localization
  85. GRB 250106A: SVOM/VT 2nd optical deep observation
  86. GRB 250101A: J band upper limit by SYSU 80cm telescope
  87. GRB 250107A: Fermi GBM Final Real-time Localization
  88. GRB 250106A: NOT optical observations
  89. GRB 250103B: REM optical/NIR upper limits
  90. GRB 250101A: REM optical/NIR counterpart detection
  91. GRB 250106A: Swift-XRT observations
  92. GRB 250106A: SVOM/VT optical candidate
  93. GRB 250106A: Swift ToO observations
  94. GRB 250106A: SVOM detection of a long burst
  95. Fermi trigger No 757753930: Global MASTER-Net observations report
  96. GRB 241229A: SVOM/VT optical upperlimit
  97. GRB 250103B: Swift-XRT refined Analysis
  98. GRB 250103B: LCO/1m optical afterglow candidate detection
  99. GRB 250103A: Bassano Bresciano Observatory upper limit
  100. GRB 250103B: VLT/X-shooter spectroscopic redshift z = 1.416

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