Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

11836 results found.

  1. GRB 241030B: Fermi GBM Final Real-time Localization
  2. GRB 241030A: Fermi-LAT detection
  3. GRB 241030A: Swift/UVOT Detection
  4. GRB 241030A: Swift detection of a burst with a bright optical counterpart
  5. EP241021a: ATCA radio observations
  6. GRB 241029A: Fermi GBM Observation
  7. Fermi trigger No 751861204: Global MASTER-Net observations report
  8. Konus-Wind detection of GRB 241025A
  9. GRB 241025A: further SAO RAS optical observations
  10. GRB 241026A: BTA and Zeiss-1000 optical observations
  11. GRB 241026A Fermi GBM Analysis
  12. GRB 241025A: SAO RAS optical observations
  13. EP241021a: further SAO RAS optical observations
  14. EP241026a (GRB 241026A): EP on-board trigger and follow-up observation
  15. GRB 241026A: Swift-XRT refined Analysis
  16. GRB 241026A: SAO RAS observations of possible optical afterglow
  17. GRB 241026A: Swift detection of a burst
  18. Swift GRB241026.95: Global MASTER-Net observations report
  19. GRB241025A: 1.3m DFOT optical afterglow detection
  20. LIGO/Virgo/KAGRA S241009l: Upper limits from Swift/BAT-GUANO
  21. Fermi trigger No 751554401: Global MASTER-Net observations report
  22. Fermi GRB 241025A: Global MASTER-Net observations report
  23. GRB 241001A: ATCA radio observations
  24. EP241021a: VLT/FORS2 redshift z = 0.75
  25. Fermi trigger No 751449953: Global MASTER-Net observations report
  26. EP241021a: SAO RAS optical observations
  27. EP241021a: EP-FXT follow-up observation update
  28. GRB241017A: 1.3m DFOT optical upper limit
  29. EP241021a: EP detection of a fast X-ray transient
  30. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  31. Konus-Wind detection of GRB 241018A
  32. GRB 241018A/sb24101802: Mephisto optical upper limit
  33. GRB 240727A: VIRT Optical Upper Limit
  34. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  35. Fermi trigger No 750788395: Global MASTER-Net observations report
  36. Fermi GRB 241016B: Global MASTER-Net observations report
  37. Fermi GRB 241016A: Global MASTER-Net observations report
  38. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  39. GRB241013A: REM observations
  40. GRB 241013A: a long GRB detected by INTEGRAL
  41. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  42. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  43. GRB 241011A: Fermi GBM Final Real-time Localization
  44. GRB 241010A: Swift-XRT refined Analysis
  45. Fermi trigger No 750211959: Global MASTER-Net observations report
  46. Fermi trigger No 750291012: Global MASTER-Net observations report
  47. GRB 241010A: Swift detection of a burst with an optical counterpart
  48. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  49. GRB 241008A: Fermi-LAT detection
  50. GRB 241002B: Swift-XRT afterglow detection
  51. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  52. GRB 240910A: LBT optical observations
  53. GRB 241006A: Swift-XRT refined Analysis
  54. IceCube Alert 241006.94: Global MASTER-Net observations report
  55. GRB 241006A: Swift detection of a burst
  56. Swift GRB241006.91: Global MASTER-Net observations report
  57. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  58. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  59. Fermi trigger No 749693019: Global MASTER-Net observations report
  60. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  61. Konus-Wind detection of GRB 240926A
  62. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  63. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  64. EP240930a: Liverpool Telescope observations
  65. GRB 241002A: Swift-XRT refined Analysis
  66. GRB 241002B: GOTO optical counterpart candidate
  67. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  68. Fermi GRB 241002B: Global MASTER-Net observations report
  69. GRB 241002A: Swift detection of a burst
  70. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  71. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  72. EP240930a: GOTO optical upper limits
  73. EP EP240930a: Global MASTER-Net observations report
  74. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  75. GRB 240929A : Leavitt Observatory optical upper limit
  76. Fermi GRB 240930B: Global MASTER-Net observations report
  77. Fermi GRB 240930A: Global MASTER-Net observations report
  78. GRB 240929A long GRB detected by INTEGRAL
  79. Fermi GRB 240929A: Global MASTER-Net observations report
  80. Konus-Wind detection of GRB 240912A
  81. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  82. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  83. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  84. EP trigger ID 01709061302: the X-ray transient is likely a stellar flare event
  85. Konus-Wind detection of GRB 240905B
  86. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  87. EP240918b and EP240918c: EP-FXT follow-up observations
  88. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  89. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  90. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  91. Konus-Wind detection of GRB 240918B
  92. IPN triangulation of GRB 240918B
  93. EP trigger ID 01709059262: the X-ray transient is likely a stellar flare event
  94. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  95. LIGO/Virgo S240919bn: GOTO optical upper limits
  96. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  97. GRB 240918B: AstroSat CZTI detection
  98. LIGO/Virgo/KAGRA S240921cw: Identification of a GW compact binary merger candidate
  99. EP240919a: EP-FXT follow-up observation update
  100. EP240919a / GRB 240919A: Mondy optical upper limit

Advanced

Download all Circulars as a .tar.gz archive:
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