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"

45720 results found.

  1. Swift GRB250101.56: Global MASTER-Net observations report
  2. GRB 241217a/EP241217b: ATCA Radio Detection
  3. EP241217a: VLA Radio Detection

  4. LIGO/Virgo/KAGRA S241231du: Coverage and upper limit from MAXI/GSC observations
  5. LIGO/Virgo/KAGRA S250101k: Identification of a GW compact binary merger candidate
  6. GRB 241229B: Continued CrAO ZTSh observations
  7. LIGO/Virgo/KAGRA S241231bg: Updated NED Galaxies in the Localization Volume
  8. LIGO/Virgo/KAGRA S241231bg: Updated Sky localization and EM Bright Classification
  9. LIGO/Virgo/KAGRA S241230ev: Updated Sky localization
  10. LIGO/Virgo/KAGRA S241231bg: NED Galaxies in the Localization Volume
  11. LIGO/Virgo/KAGRA S241230bd: Updated Sky localization
  12. GRB 241229A: EP-FXT X-ray afterglow confirmation
  13. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  14. GRB 241229B: SVOM/GRM observation
  15. LIGO/Virgo/KAGRA S241231bg: Identification of a GW compact binary merger candidate
  16. EP241217A: J band upper limit by SYSU 80cm telescope
  17. LIGO/Virgo/KAGRA S241230ev: Identification of a GW compact binary merger candidate
  18. GRB 241229B: SAO RAS optical upper limit
  19. GRB 241228B: SAO RAS optical observations
  20. GRB 241229B: CrAO ZTSh possible optical counterpart of SVOM/VT confirmation
  21. GRB 241229A: SAO RAS optical observations
  22. IceCube-Cascade 241228A: Upper limits from a search for additional neutrino events in IceCube
  23. GRB 241229B: SVOM/VT optical candidate
  24. GRB 241229A: Swift-XRT observations
  25. Konus-Wind detection of GRB 241228A
  26. GRB 241229A: EP-FXT afterglow candidates
  27. EP240702a: 7DT Optical upper limits
  28. GRB 240606B: 7DT Optical upper limits
  29. Fermi trigger No 757231333: Global MASTER-Net observations report
  30. LIGO/Virgo/KAGRA S241230bd: Identification of a GW compact binary merger candidate
  31. GRB 241229B: Swift-BAT refined analysis
  32. LIGO/Virgo/KAGRA S241225v: Updated Sky localization
  33. LIGO/Virgo/KAGRA S241225c: Updated Sky localization and EM Bright Classification
  34. Fermi Gamma-ray Burst Monitor trigger 757207662/241229978 (GRB 241229C) is not a GRB
  35. GRB241229B: UVOT upper limits
  36. GRB 241229C: Fermi GBM Final Real-time Localization
  37. GRB 241228B: D50 optical detection
  38. GRB 241228B: Fermi GBM Observation
  39. GRB 241228B: Swift-XRT afterglow detection
  40. GRB 241229B: Fermi GBM Observation
  41. GRB 241229A: Swift ToO observations
  42. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  43. GRB 241228A: Mondy optical afterglow observations
  44. GRB 241229B: Swift-XRT refined Analysis
  45. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  46. Swift GRB 241229B: Global MASTER-Net observations report
  47. GRB 241229A: GOTO optical upper limits
  48. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  49. GRB 241228A: NOT optical upper limits
  50. GRB 241228B: LCO optical observation
  51. GRB 241228A: Swift-BAT refined analysis
  52. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  53. GRB 241229B: Swift detection of a burst
  54. GRB 241229B: Fermi GBM Final Real-time Localization
  55. GRB 241229A: SVOM detection of a long burst
  56. Fermi GRB 241228B: Global MASTER-Net observations report
  57. GRB 241228A: Fermi GBM Observation
  58. GRB241228B: GROWTH-India Telescope optical observations
  59. Swift GRB 241228A: Global MASTER-Net observations report
  60. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  61. GRB 241228B: GOTO24jmz optical follow-up observations
  62. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  63. GRB 241228A: GROWTH-India telescope optical upper limit
  64. GRB 241228B: Swift ToO observations
  65. GRB 241228B: TRT optical counterpart confirmation
  66. GRB 241228A: Swift-XRT refined Analysis
  67. GRB 241228A: Swift/UVOT Upper Limits
  68. GRB 241228B: GOTO possible optical counterpart candidate
  69. GRB 241228A: Enhanced Swift-XRT position
  70. GRB 241228B: Fermi GBM Final Real-time Localization
  71. GRB 241228A: Swift detection of a burst
  72. IceCube-241224A: Upper limits from a search for additional neutrino events in IceCube
  73. LIGO/Virgo/KAGRA S241225c: Two counterpart neutrino candidates from IceCube neutrino searches
  74. GRB 241223A: GRBAlpha detection
  75. GRB 241212A: VZLUSAT-2 detection
  76. GRB 241217A/EP241217b: continued SOAR observations
  77. Fermi GRB 241226A: Global MASTER-Net observations report
  78. GRB 241226A: Fermi GBM Final Real-time Localization
  79. EP241223a: Mondy AZT-33IK optical observations
  80. GRB 241029A: LCO optical observation
  81. GRB 241223A: Swift-XRT observations
  82. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  83. GRB 241029A: AbAO AS-32 optical observations
  84. GRB 241223A: Fermi GBM Detection
  85. Fermi trigger No 756678579: Global MASTER-Net observations report
  86. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  87. EP241223a
  88. IceCube-241224A - IceCube observation of a high-energy neutrino candidate track-like event
  89. IceCube Alert 241224.30: Global MASTER-Net observations report
  90. GRB 241219A: SVOM/GRM observation
  91. EP241223a: Global MASTER-Net observations report
  92. EP241223a: EP-WXT detection of a fast X-ray transient
  93. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  94. GRB241113A: 7DT Optical upper limits
  95. Fermi Gamma-ray Burst Monitor trigger 756678579 / 241223854 is not a GRB
  96. Fermi GRB 241223A: Global MASTER-Net observations report
  97. GRB 241223A: GOTO optical observations summary
  98. GRB 241105A: JWST photometric observations of the host galaxy
  99. GRB 241223A: Swift ToO observations
  100. EP241217a: e-MERLIN radio 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