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"

27378 results found.

  1. SVOM GRB260102A: Global MASTER-Net observations report
  2. Fermi GBM Sub-Threshold Detection of GRB 260102A
  3. GRB 260102A: EP-FXT follow-up observation
  4. EP260101a: Global MASTER-Net observations report
  5. GRB 260102A: LCO optical upper limits
  6. GRB 260102A: Swift-XRT observations
  7. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  8. GRB 260101A: Fermi GBM Observation
  9. EP260101a: refined analysis of the EP-WXT and EP-FXT observations
  10. GRB 260102A: SVOM detection of a burst
  11. GRB 260101A: NOT spectroscopic observations
  12. GRB 260101A: SVOM/GRM observation
  13. GRB 260101A: Swift-XRT refined Analysis
  14. Swift GRB 260101A: Global MASTER-Net observations report
  15. GRB 260101A: Enhanced Swift-XRT position
  16. EP260101a: Einstein Probe detection of an X-ray transient
  17. GRB 260101A: LCO detection of the optical counterpart
  18. GRB 260101A: Swift detection of a burst with an optical counterpart
  19. GRB 260101A: Fermi GBM Final Real-time Localization
  20. SVOM GRB251231.57: Global MASTER-Net observations report
  21. GRB 251230A: GRANDMA/TAROT Early Detection
  22. GRB 251230A/EP251230a: Optical upper limit with Kinder observations
  23. EP251229a: Optical upper limit with Kinder observations
  24. GRB 251230A: 1.3m DFOT optical upper limit
  25. GRB 251230A: Swift-XRT refined Analysis
  26. GRB 251222A: Mondy Optical Observations
  27. EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
  28. GRB 251230A: Swift/UVOT detection
  29. GRB251230A: 7DT optical upper limits
  30. GRB 251230A: GOTO optical upper limit
  31. EP251229a: NOT optical upper limits
  32. GRB 251230A / EP251230a: SVOM/VT optical observation
  33. EP251229a: refined analysis of the EP-WXT and EP-FXT observations
  34. GRB 251230A: Enhanced Swift-XRT position
  35. GRB 251230A: Early optical counterpart detection by LCO.
  36. EP-WXT trigger 01709250662 Mephisto and 50cm telescope follow-up
  37. EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
  38. LIGO/Virgo/KAGRA S251112cm: Candidates from the NSF-DOE Vera C. Rubin Observatory
  39. Swift GRB 251230A: Global MASTER-Net observations report
  40. EP251229a: Global MASTER-Net observations report
  41. EP251229a: Einstein Probe detection of an X-ray transient
  42. GRB 251230A: Swift detection of a burst with a bright optical counterpart
  43. GRB 251226A: Glowbug gamma-ray detection
  44. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  45. Fermi GRB 251228A: Global MASTER-Net observations report
  46. GRB 251226A: SVOM/GRM observation
  47. GRB 251226A: GECAM-B detection
  48. SVOM GRB251227.07: Global MASTER-Net observations report
  49. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  50. IceCube Alert 251225.84: Global MASTER-Net observations report
  51. GRB 251222A/EP251222b: Optical detection with Kinder observations
  52. EP251222a: Optical upper limit with Kinder observations
  53. GRB 251221A: Swift-BAT refined analysis
  54. GRB 251205A: Kilonova-Catcher optical afterglow detection
  55. GRB 251222A: AbAO optical observations
  56. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  57. GRB 251222A: ZTSH BVRI optical observations
  58. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  59. GRB 251222A: Continued 1.3m DFOT optical observation
  60. EP251220a: 3.6m DOT optical afterglow detection
  61. GRB 251222A: Fermi GBM Observation
  62. EP251220a: CrAO ZTSh optical observations
  63. EP251221a: PRIME upper limit
  64. EP251222a: Global MASTER-Net observations report
  65. EP251221a: Liverpool Telescope upper limits
  66. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  67. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  68. GRB 251222A: Swift-XRT afterglow detection
  69. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  70. EP251222a: NTT/ULTRACAM optical observations
  71. GRB 251222A / EP251222b: GOTO optical counterpart detection
  72. GRB 251222A / EP251222b: LCO optical observations
  73. GRB 251222A: 1.3m DFOT optical detection
  74. GRB251221A: 7DT optical upper limits
  75. EP251222a: GSP Optical Counterpart Detection
  76. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  77. EP251222a: Einstein Probe detection of an X-ray transient
  78. EP251221a: Global MASTER-Net observations report
  79. GRB 251222A: PRIME near-infrared detection
  80. EP251221a: NOT optical upper limit
  81. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  82. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  83. IPN triangulation of GRB 251220B (short)
  84. GRB 251222A: BALROG localization (Fermi Trigger / GRB 251222712)
  85. GRB 251222A: SVOM/VT optical candidate
  86. GRB 251222A: SVOM detection of a long burst
  87. SVOM GRB251222A: Global MASTER-Net observations report
  88. EP251220a: PRIME upper limit
  89. GRB 251221A: PRIME near-infrared observation
  90. GRB 251221A: UAFO and Mondy optical upper limit
  91. GRB 251221A: Swift-XRT refined Analysis
  92. EP251221a: Einstein Probe detection of a fast X-ray transient
  93. GRB 251221A: Swift/UVOT Upper Limits
  94. GRB 251221A: Enhanced Swift-XRT position
  95. GRB 251221A: Fermi GBM Observation
  96. GRB 251220B: SVOM/GRM observation of a short burst
  97. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  98. EP 251220a: GOTO optical counterpart detection
  99. GRB 251221A: COLIBRÍ detection of the optical counterpart
  100. EP 251220a: COLIBRÍ detection of the optical counterpart

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