Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

37520 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 747839931/240912555 is not a GRB
  2. GRB 240912A : INTEGRAL SPI ACS LIGHT CURVE
  3. GRB 240912B: Fermi GBM Final Real-time Localization
  4. GRB 240912A: NOT optical spectroscopy
  5. GRB 240912A: Enhanced Swift-XRT position
  6. GRB 240912A: Redshift from OSIRIS+/GTC
  7. GRB 240910A: Redshift from OSIRIS+/GTC
  8. GRB 240912A: Swift detection of a burst with an optical counterpart
  9. GRB 240912A: Fermi GBM Final Real-time Localization
  10. GRB 240910A: Fermi GBM Observation
  11. GRB 240910A: NOT optical observations
  12. GRB 240911A : a likely weak GRB detected by SVOM/ECLAIRs
  13. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  14. GRB 240910A: JinShan optical observations
  15. GRB 240910A: GOTO candidate optical counterpart
  16. GRB 240710A: SVOM/GRM observation
  17. GRB 240910A: Swift ToO observations
  18. IPN triangulation of GRB 240905B (short)
  19. GRB 240825A: 7DT Optical Upper Limit
  20. GRB 240905E: SVOM/VT optical observations
  21. GRB 240905E: SVOM/VT optical observations (duplicate submission of GCN 37453)
  22. GRB 240910A: GRBAlpha detection
  23. GRB 240910B: Fermi GBM Final Real-time Localization
  24. GRB 240910A: SVOM/GRM observation
  25. EP240908a: Mondy and AbAO follow-up observations
  26. Fermi GRB 240910A: Global MASTER-Net observations report
  27. GRB 240910A: Fermi GBM Final Real-time Localization
  28. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  29. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  30. GRB 240905B: Fermi GBM Observation
  31. Fermi trigger No 747553301: Global MASTER-Net observations report
  32. GRB 240905B: GOTO optical upper limits
  33. Fermi GRB 240908A: Global MASTER-Net observations report
  34. GRB 240908A: Fermi GBM Final Real-time Localization
  35. GRB 240801A: SVOM/GRM observation
  36. GRB 240905E: GIT optical upper limit
  37. GRB 240905B: Swift-XRT observations
  38. GRB 240905E: Gaoyazi/GOT optical upper limits
  39. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  40. GRB 240905B: Fermi-LAT detection
  41. GRB 240905B: Swift ToO observations
  42. GRB 240905E: J-band observations with WINTER
  43. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  44. GRB 240905E: AKO Optical Upper Limit
  45. GRB 240905E: SVOM/C-GFT optical upper limit
  46. GRB 240905E: OHP/MISTRAL T193 optical upper limit
  47. Fermi GRB 240905D: Global MASTER-Net observations report
  48. Fermi GRB 240905A: Global MASTER-Net observations report
  49. GRB 240905E: NOT optical upper limits
  50. GRB 240905E: REM optical/NIR upper limits
  51. GRB 240902B: AstroSat CZTI detection of a long burst
  52. GRB 240905E: Swift-XRT refined Analysis
  53. GRB 240902A: AstroSat CZTI detection of a long burst
  54. GRB 240905E: SVOM/GRM observation
  55. GRB 240905E: LCOGT Optical Upper Limit
  56. GRB 240905E: Swift/UVOT Upper Limits
  57. GRB 240905E: SAO RAS optical upper limit
  58. GRB 240825A: Montarrenti Observatory optical follow-up observations
  59. GRB 240905E: Nanshan/HMT optical upper limit
  60. Swift GRB 240905E: Global MASTER-Net observations report
  61. GRB 240905E: Swift detection of a burst
  62. GRB 240819A: Optical upper limits from TESS
  63. GRB 240905D: AstroSat CZTI detection
  64. GRB 240905A: SVOM/GRM observation
  65. Fermi GRB 240905B: Global MASTER-Net observations report
  66. GRB 240905D: Fermi GBM Final Real-time Localization
  67. GRB 240905B: AstroSat CZTI detection and localization
  68. GRB 240905C: Fermi GBM Final Real-time Localization
  69. GRB 240905B: Fermi GBM Final Real-time Localization
  70. GRB 240825A: ATCA Detection of Radio Counterpart
  71. Swift GRB 240904A: Global MASTER-Net observations report
  72. GRB 240905A: Fermi GBM Final Real-time Localization
  73. Fermi Gamma-ray Burst Monitor trigger 747163821/240904729 is not a GRB
  74. Fermi trigger No 747163821: Global MASTER-Net observations report
  75. GRB 240904A: Swift detection of a burst
  76. GRB 240828A: SVOM/GRM observation
  77. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  78. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  79. Fermi Gamma-ray Burst Monitor trigger 240831A is not a GRB
  80. GRB 240828A: GECAM detection
  81. GRB 240831B: Fermi GBM Final Localization
  82. Fermi Gamma-ray Burst Monitor trigger 746882332/240901471 is not a GRB
  83. GRB 240825A: Magnitude Correction in SVOM/C-GFT Optical Observations
  84. GRB 240825A: MeerLICHT afterglow detection
  85. Fermi trigger No 746923430: Global MASTER-Net observations report
  86. GRB 240828A: SAO RAS AS-500(2) optical observations
  87. GRB 240821A: VLT spectroscopic observations
  88. Fermi trigger No 746882332: Global MASTER-Net observations report
  89. GRB 240825A: TSHAO Optical Upper Limit
  90. GRB 240829B: GRBAlpha detection
  91. GRB240828B: REM optical/NIR upper limits
  92. Fermi trigger No 746816563: Global MASTER-Net observations report
  93. GRB 240828B: AbAO optical upper limit
  94. GRB 240831A: Fermi GBM Final Real-time Localization
  95. GRB 240825A: SOAR observations
  96. GRB 240828B: Mephisto optical upper limit
  97. GRB 240828B: GRANDMA Optical Upper Limit
  98. GRB 240829A: Swift-BAT refined analysis
  99. GRB 240825A: Swift-BAT refined analysis
  100. GRB 240825A: MeerKAT detection

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