Skip to main content
End of Swift Science Operations, CHIME Notices Unavailable During Upgrade. 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"

43153 results found.

  1. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  2. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  3. EP241107a: Kinder optical follow-up observations
  4. GRB 241025A: radio detection with the VLA
  5. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  6. EP241107a: AKO Optical Afterglow Follow-Up Observations
  7. EP241107a: GSP detects optical counterpart
  8. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  9. GRB 241107A: SVOM/GRM detection of a short burst
  10. GRB 241105A: EP-FXT follow-up observations
  11. GRB 241105A: SVOM/GRM observation
  12. EP241107a: OHP/T193 photometric and spectroscopic observations
  13. GRB 241105a: PRIME near-infrared upper limits
  14. EP241107a: FTW Optical and NIR observations of the optical counterpart
  15. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  16. EP241107a: GIT optical observations
  17. EP241107a: Global MASTER-Net observations report
  18. EP241107a: SVOM/C-GFT optical observations
  19. EP241107a: AKO Optical Afterglow Detection
  20. GRB 241025A: LBT optical observations
  21. GRB241105A: Gemini-South Optical Afterglow Detection
  22. EP241107a: EP on-board trigger and autonomous follow-up observation
  23. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  24. GRB 241105A: Swift/UVOT Detection
  25. EP241101a: CrAO ZTSH optical observations
  26. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  27. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  28. GRB 241105A: BOOTES-7 optical detection
  29. GRB 241030A: Mondy optical observations
  30. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  31. Konus-Wind detection of GRB 241105A (short with extended emission)
  32. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  33. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  34. Konus-Wind detection of GRB 241021A
  35. GRB 241105A: SVOM/VT optical afterglow observations
  36. GRB 241105A: Swift-XRT afterglow detection
  37. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  38. GRB 241104A: Swift-XRT observations
  39. GRB 240511A: LCO upper limits
  40. GRB 241104A: Fermi GBM Observation
  41. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  42. GRB 241105A: Swift ToO observations
  43. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  44. GRB 241104A: Swift ToO observations
  45. GRB 241104A: NOT optical non-detection
  46. GRB 241105A: GOTO tentative optical counterpart candidate
  47. Fermi GRB 241105A: Global MASTER-Net observations report
  48. GRB 241104A: SVOM/VT optical candidate
  49. GRB 241105A: Fermi GBM Final Real-time Localization
  50. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  51. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  52. GRB 241104A: SVOM/GRM observation
  53. EP241104a: EP detection of GRB 241104A X-ray emission
  54. GRB 241010A: host galaxy redshift z = 0.977
  55. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  56. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  57. GRB 240821A: further radio observations with the VLA
  58. Fermi GRB 241104A: Global MASTER-Net observations report
  59. GRB 241104A: Fermi GBM Final Real-time Localization
  60. GRB 241030A: GRBAlpha detection
  61. EP241101a: EP-FXT observations update
  62. EP241103a: GIT optical upper limit
  63. EP241021a: OHP/T193 further optical observations
  64. LIGO/Virgo/KAGRA S241104a: Retraction of GW compact binary merger candidate
  65. Fermi trigger No 752365806: Global MASTER-Net observations report
  66. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  67. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  68. EP241103a: GOTO optical upper limit
  69. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  70. EP241101a: Possible detection of an optical counterpart with FTW
  71. EP241103a: Swift XRT detection and improved X-ray position
  72. EP241021a: continued SOAR observations
  73. EP241101a: Optical upper limits with Kinder observations
  74. EP241101a: OHP/T193 optical observations
  75. EP241103a: Gemini optical limits
  76. EP241103a: EP observation update
  77. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  78. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  79. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  80. EP241103a: GSP optical upper limit
  81. EP241103A: LCO optical observations
  82. EP241103a: Global MASTER-Net observations report
  83. EP241103a: an X-ray transient detected by Einstein Probe
  84. GRB 241030A: Rapid release of TESS data.
  85. EP241101a: Global MASTER-Net observations report
  86. GRB 241029A: GRBAlpha detection
  87. EP241101a: BOOTES-7 optical upper limit
  88. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  89. S241102cy: Identification of a GW compact binary merger candidate
  90. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  91. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  92. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  93. GRB241030A: OHP/T193 optical observations
  94. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  95. EP241101a: EP-WXT detection of a fast X-ray transient
  96. Swift GRB 241101A: Global MASTER-Net observations report
  97. GRB 241101A: FRAM-ORM optical limit
  98. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  99. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  100. EP241021a: Upper limit from Konus-Wind observations

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