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"

28108 results found.

  1. Fermi trigger No 785388351: Global MASTER-Net observations report
  2. EP251118A: 1.3m DFOT optical afterglow detection
  3. GRB 251118A: Swift/UVOT Detection
  4. EP251118a / GRB 251118C: SAO RAS optical observations
  5. GRB 251118A: Glowbug gamma-ray detection
  6. GRB 251118A: Fermi GBM Observation
  7. GRB 251118A: Swift-XRT afterglow detection
  8. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  9. EP251118a: Optical detection with Kinder observations
  10. LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
  11. GRB 251118A: NuSTAR detection of bright prompt emission
  12. EP251118a / GRB 251118C: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 1-m telescope at CTIO
  13. GRB 251116C: NOT optical observations
  14. GRB 251118C: Glowbug gamma-ray detection of the fast X-ray transient EP251118A
  15. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  16. GRB 251117A: Swift-XRT observations
  17. EP251118A / GRB 251118C : MASTER optical counterpart observations
  18. GRB 251118C: SVOM/GRM observation of a possible gamma-ray counterpart of EP251118a
  19. GRB 251119A: SVOM trigger sb25111901 is not a GRB
  20. EP251118a: VLT near-infrared observation
  21. GRB 251116D: SVOM/GRM observation of a long GRB
  22. GRB 251119A: SVOM detection of a possible burst
  23. EP251118a: Global MASTER-Net observations report
  24. LAT GRB251118.86: Global MASTER-Net observations report
  25. EP251118a: NOT candidate optical counterpart
  26. EP251118a: Einstein Probe detected of a fast X-ray transient
  27. Fermi GRB 251118B: Global MASTER-Net observations report
  28. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  29. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  30. GRB 251117A: AstroSat CZTI detection
  31. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  32. LIGO/Virgo/KAGRA S251117dq: Updated Sky localization
  33. GRB 251115A: Swift-XRT observations
  34. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  35. GRB 251117A: SVOM/GRM observation of a short burst
  36. LAT GRB251117.51: Global MASTER-Net observations report
  37. LIGO/Virgo/KAGRA S251117dq: Identification of a GW compact binary merger candidate
  38. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  39. LIGO/Virgo/KAGRA S251112cm: WFST follow-up observations and preliminary results
  40. GRB 251116C: Swift-XRT observations
  41. LIGO/Virgo/KAGRA S251116en: Updated Sky localization
  42. GRB 251116D: Glowbug gamma-ray detection
  43. EP251023a: Assy AZT-20 optical observations
  44. EP251023a: UAFO and AbAO optical observations
  45. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  46. GRB 251116C: SVOM/VT optical upper limit
  47. GRB 251025B: further Mondy optical observations
  48. GRB 251111A: Mondy optical upper limit
  49. GRB 251116B: EP-FXT follow-up observation
  50. LIGO/Virgo/KAGRA S251116en: Identification of a GW compact binary merger candidate
  51. LIGO/Virgo/KAGRA S251112cm: Observations with the NSF-DOE Vera C. Rubin Observatory
  52. GRB 251116B: LCO optical upper limits
  53. GRB 251116C: LCO optical upper limits
  54. SVOM GRB251116C: Global MASTER-Net observations report
  55. GRB 251116B: SVOM detection of a burst
  56. IceCube-Cascade 251112A: Upper limits from a search for additional neutrino events in IceCube
  57. LIGO/Virgo/KAGRA S251112cm: GRANDMA observations of the skymap
  58. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  59. Fermi GRB 251115A: Global MASTER-Net observations report
  60. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  61. LIGO/Virgo/KAGRA S251112cm: DECam GW-MMADS candidates
  62. LIGO/Virgo/KAGRA S251112cm: Updated Sky localization and false alarm rate estimate
  63. GRB 251113A: Glowbug gamma-ray detection
  64. GRB 251112A: Swift-BAT refined analysis
  65. Fermi trigger No 784717756: Global MASTER-Net observations report
  66. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  67. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  68. Fermi GRB 251114A: Global MASTER-Net observations report
  69. LIGO/Virgo/KAGRA S251112cm: FTW observations of galaxies within localization region
  70. Fermi GRB 251113A: Global MASTER-Net observations report
  71. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  72. GRB 251112A: Swift/UVOT Upper Limits
  73. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  74. GRB 251112A: Swift-XRT refined Analysis
  75. GRB 251112B: MAXI/GSC detection
  76. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  77. LIGO/Virgo/KAGRA S251112cm: Initial GOTO-South observations
  78. GRB 251108B: Glowbug gamma-ray detection
  79. Swift Trigger 1413695: a possible GRB 251112A
  80. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  81. Fermi trigger No 784621743: Global MASTER-Net observations report
  82. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 3-Initial Localization Volume
  83. GRB251111A: 1.3m DFOT optical upper limit
  84. LIGO/Virgo/KAGRA S251112cm: Identification of a GW compact binary merger candidate
  85. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  86. GRB 251111A: Swift-XRT afterglow detection
  87. GRB 251111A: SVOM/VT optical observations with X-band data
  88. SVOM GRB251111.42: Global MASTER-Net observations report
  89. GRB 251111A: Swift-XRT observations
  90. SVOM GRB251111.22: Global MASTER-Net observations report
  91. GRB 251111A: EP-FXT counterpart detection
  92. GRB 251013C: Chandra X-ray observations and jet break detection
  93. GRB 251111A: SVOM/VT optical observations with VHF data
  94. GRB 251111A: LCO optical observation
  95. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  96. GRB 251103B: Swift-BAT refined analysis
  97. GRB 251106A: Swift/UVOT Upper Limits
  98. LIGO/Virgo/KAGRA S251108fi: DDOTI Optical Candidate
  99. LIGO/Virgo/KAGRA S251108fi: One counterpart neutrino candidate from IceCube neutrino searches
  100. IceCube-Cascade 251107A: Upper limits from a search for additional neutrino events in IceCube

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