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"

44271 results found.

  1. GRB 241229B: NUTTelA-TAO / BSTI Optical Limits
  2. GRB 241228A: Mondy optical afterglow observations
  3. GRB 241229B: Swift-XRT refined Analysis
  4. IceCube-241224A: No transient candidates from the Zwicky Transient Facility
  5. Swift GRB 241229B: Global MASTER-Net observations report
  6. GRB 241229A: GOTO optical upper limits
  7. GRB 241228B: VLT/X-shooter redshift of z = 2.674
  8. GRB 241228A: NOT optical upper limits
  9. GRB 241228B: LCO optical observation
  10. GRB 241228A: Swift-BAT refined analysis
  11. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  12. GRB 241229B: Swift detection of a burst
  13. GRB 241229B: Fermi GBM Final Real-time Localization
  14. GRB 241229A: SVOM detection of a long burst
  15. Fermi GRB 241228B: Global MASTER-Net observations report
  16. GRB 241228A: Fermi GBM Observation
  17. GRB241228B: GROWTH-India Telescope optical observations
  18. Swift GRB 241228A: Global MASTER-Net observations report
  19. GRB 241228B: LCOGT photometry of the likely optical counterpart GOTO24jmz
  20. GRB 241228B: GOTO24jmz optical follow-up observations
  21. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  22. GRB 241228A: GROWTH-India telescope optical upper limit
  23. GRB 241228B: Swift ToO observations
  24. GRB 241228B: TRT optical counterpart confirmation
  25. GRB 241228A: Swift-XRT refined Analysis
  26. GRB 241228A: Swift/UVOT Upper Limits
  27. GRB 241228B: GOTO possible optical counterpart candidate
  28. GRB 241228A: Enhanced Swift-XRT position
  29. GRB 241228B: Fermi GBM Final Real-time Localization
  30. GRB 241228A: Swift detection of a burst
  31. IceCube-241224A: Upper limits from a search for additional neutrino events in IceCube
  32. LIGO/Virgo/KAGRA S241225c: Two counterpart neutrino candidates from IceCube neutrino searches
  33. GRB 241223A: GRBAlpha detection
  34. GRB 241212A: VZLUSAT-2 detection
  35. GRB 241217A/EP241217b: continued SOAR observations
  36. Fermi GRB 241226A: Global MASTER-Net observations report
  37. GRB 241226A: Fermi GBM Final Real-time Localization
  38. EP241223a: Mondy AZT-33IK optical observations
  39. GRB 241029A: LCO optical observation
  40. GRB 241223A: Swift-XRT observations
  41. LIGO/Virgo/KAGRA S241225v: Identification of a GW compact binary merger candidate
  42. GRB 241029A: AbAO AS-32 optical observations
  43. GRB 241223A: Fermi GBM Detection
  44. Fermi trigger No 756678579: Global MASTER-Net observations report
  45. LIGO/Virgo/KAGRA S241225c: Identification of a GW compact binary merger candidate
  46. EP241223a
  47. IceCube-241224A - IceCube observation of a high-energy neutrino candidate track-like event
  48. IceCube Alert 241224.30: Global MASTER-Net observations report
  49. GRB 241219A: SVOM/GRM observation
  50. EP241223a: Global MASTER-Net observations report
  51. EP241223a: EP-WXT detection of a fast X-ray transient
  52. EP241113a: Non-detection in Radio Follow-up Observations with eMERLIN
  53. GRB241113A: 7DT Optical upper limits
  54. Fermi Gamma-ray Burst Monitor trigger 756678579 / 241223854 is not a GRB
  55. Fermi GRB 241223A: Global MASTER-Net observations report
  56. GRB 241223A: GOTO optical observations summary
  57. GRB 241105A: JWST photometric observations of the host galaxy
  58. GRB 241223A: Swift ToO observations
  59. EP241217a: e-MERLIN radio observations
  60. GRB 241223A: BALROG localization (Fermi Trigger 756648531 / GRB 241223506)
  61. GRB 241223A: Fermi GBM Final Real-time Localization
  62. GRB 241217A / EP241217b: Non-detection in ATCA Radio Follow-up Observations
  63. The EP-WXT trigger 01709129287 is likely a flaring star
  64. Fermi trigger No 756447119: Global MASTER-Net observations report
  65. GRB 241209B: host galaxy detection and GTC/OSIRIS+ spectroscopy
  66. Fermi Gamma-ray Burst Monitor trigger 756447119/241221175 is not a GRB
  67. Fermi GRB 241221A: Global MASTER-Net observations report
  68. GRB 241221A: Fermi GBM Final Real-time Localization
  69. GRB 241217A/EP241217b: SOAR afterglow detection
  70. EP241217a: Liverpool Telescope optical upper limit
  71. EP241021a: VLA radio detection
  72. GRB 241218A: Mondy AZT-33IK optical upper limit
  73. EP241217a : Leavitt Observatory optical upper limit
  74. GRB 241217A/EP241217b: tentative VLT spectroscopic redshift z=1.879
  75. EP241217a: 1.6m Mephisto multi-band optical observations
  76. GRB 241217a/EP241217B: 1.6m Mephisto optical upper limits
  77. GRB 241218A: Swift/UVOT Upper Limits
  78. EP241217a: optical upper limit with the Liverpool Telescope
  79. GRB 241209B: EP-FXT afterglow detection
  80. Konus-Wind detection of GRB 241204A (short/hard)
  81. GRB 241218A: NOT optical upper limits
  82. GRB 241218A: Swift-BAT refined analysis
  83. GRB 241217A / EP241217B: GRANDMA/T1MPicduMidi optical upperlimits
  84. EP 241217a: NIR detection with P200/WIRC
  85. EP 241217a: Possible J-band detection with WINTER
  86. GRB 241217A/EP241217B: Fermi-GBM Sub-Threshold Detection
  87. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  88. GRB 241217A / EP241217b: Nanshan/HMT optical upper limit
  89. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  90. GRB 241217A / EP241217b: NOT optical upper limits
  91. GRB 241218A: REM optical upper limit
  92. GRB 241217A/EP241217b: REM optical/NIR upper limits
  93. EP241217a: REM optical/NIR upper limits
  94. GRB 241217a: Liverpool Telescope optical follow-up
  95. EP241217a: Liverpool Telescope optical follow-up
  96. GRB 241218A: Swift-XRT refined Analysis
  97. EP241217a: NOT optical observations
  98. EP241217a: GROWTH-India Telescope optical observations
  99. GRB 241218A: NUTTelA-TAO / BSTI Optical Limits
  100. EP241119a: 7DT Optical upper limits

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