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"

97 results found.

  1. EP260321a: Gemini-South confirmation of a supernova
  2. EP260210a: refined analysis of the EP-FXT observation
  3. GRB 260208B: Swift-XRT observations
  4. Konus-Wind detection of GRB 260131A/B
  5. EP260128a / GRB 260128A: COLIBRÍ optical upper limit
  6. GRB 251222A / EP251222b: SVOM/VT optical rebrightening
  7. Fermi GRB 251214A: Global MASTER-Net observations report
  8. GRB 251211B: AstroSat CZTI detection
  9. GRB 250818B: MeerKAT Detection
  10. EP250812a: NOT, NTT, and GS observations
  11. GRB 250625A: Swift-XRT refined Analysis
  12. GRB 250520A: Gemini-South optical afterglow detection
  13. GRB 250520A: Gemini-South optical observations
  14. EP250508a: Gemini NIR upper limits
  15. GRB 250322A: Gemini-South optical observations
  16. Fermi trigger No 763933627: Global MASTER-Net observations report
  17. EP250225a: Global MASTER-Net observations report
  18. EP250108a / SN2025kg: Gemini GMOS-S confirmation of an associated broad-lined SN Ic
  19. Integral GRB241215.58: Global MASTER-Net observations report
  20. GRB 241212A: AstroSat CZTI detection
  21. Fermi trigger No 754701230: Global MASTER-Net observations report
  22. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  23. GRB241105A: Gemini-South Optical Afterglow Detection
  24. EP241021a: Gemini-South detection of optical rebrightening
  25. Konus-Wind detection of GRB 241025A
  26. Fermi trigger No 749693019: Global MASTER-Net observations report
  27. GRB 240821A: Fermi GBM Observation
  28. GRB 240805B: Swift/UVOT Upper Limits
  29. LIGO/Virgo/KAGRA S240615dg: Identification of a GW compact binary merger candidate
  30. GRB 240606B: Fermi GBM Observation
  31. GRB 240513A: AstroSat CZTI detection
  32. Fermi GRB 240428A: Global MASTER-Net observations report
  33. GRB 231215A : MITSuME Akeno optical afterglow candidate detection
  34. GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
  35. GRB 231111A: Swift detection of a burst with an optical counterpart
  36. Fermi GRB 231030B: Global MASTER-Net observations report
  37. GRB 230204B: Fermi GBM detection
  38. GRB 230102A: Fermi GBM Observation
  39. GRB221009A: Gemini-South Optical Afterglow Detection
  40. GRB 220803A: AstroSat CZTI detection
  41. IceCube Alert 220513.97: Global MASTER-Net observations report
  42. GRB 220308B: Fermi GBM detection
  43. Fermi GRB 220309A: Global MASTER-Net observations report
  44. IceCube Alert 220202.49: Global MASTER-Net observations report
  45. Fermi GRB 211212A: Global MASTER-Net observations report
  46. Fermi trigger No 653093506: Global MASTER-Net observations report
  47. Konus-Wind detection of GRB 210619B
  48. Fermi trigger No 645047470: Global MASTER-Net observations report
  49. ZTF21aayokph (AT2021lfa): Redshift from Gemini South
  50. Fermi trigger No 641601187: Global MASTER-Net observations report
  51. GRB 210102B: MAXI/GSC detection
  52. GRB 201026A: Swift/UVOT Upper Limits
  53. GRB 201006A: Swift/UVOT Upper Limits
  54. Fermi GRB 200909A: Global MASTER-Net observations report
  55. Fermi GRB 200420A: Global MASTER-Net observations report
  56. LIGO/Virgo S200114f: Gemini Spectra of AT 2020vu, AT 2020vw, AT 2020vy, and AT 2020vz
  57. Fermi trigger No 600666048: Global MASTER-Net observations report
  58. Swift GRB191226.02: Global MASTER-Net observations report
  59. LIGO/Virgo S190814bv Global MASTER-Net observations report
  60. HAWC-190806A: upper limits from INTEGRAL SPI-ACS and IBIS prompt observation
  61. LIGO/Virgo S190602aq: Identification of a GW compact binary merger candidate
  62. GRB 190311A: Swift/UVOT Detection
  63. GRB 171205A: Swift-XRT refined Analysis
  64. GRB 170921A: Swift-XRT refined Analysis
  65. Konus-Wind observation of GRB 170808B
  66. GRB 170803A: Swift/UVOT Detection
  67. GRB 161219B: Swift-XRT refined Analysis
  68. GRB 161213A: POLAR Observation
  69. GRB 160525B: Swift/UVOT Detection
  70. GRB 150831A: Swift/UVOT Upper Limits
  71. Swift Trigger 646423 is GS 1354-645
  72. GRB 150530A: Swift/UVOT Upper Limits
  73. Konus-Wind observation of GRB 140329A
  74. GRB 140311A: Swift/UVOT Upper Limits
  75. GRB 130427A: Zadko observatory - Gingin optical observations
  76. GRB 110213A: Swift/UVOT refined analysis
  77. Konus-Wind observation of GRB 110205A
  78. Short GRB 110106A: MASTER OT observations
  79. GRB 101017A: Swift/UVOT Observations
  80. GRB 100802A: Swift/UVOT Possible Optical Afterglow
  81. GRB100425A: Swift/UVOT Upper Limits
  82. INTEGRAL Alert n. 5995: MASTER-Net optical observations
  83. Swift/UVOT refined analysis of GRB100117A
  84. GRB 091128: Fermi GBM detection
  85. GRB 090904B: Fermi GBM detection
  86. GRB 090815B: Fermi GBM detection
  87. GRB 090423: Fermi GBM observation
  88. Fermi Detection of GRB 081102
  89. GRB080913: Swift/UVOT Upper Limits
  90. GRB 071117: Gemini Observations
  91. Swift/UVOT refined analysis of GRB070531
  92. Konus-Wind observation of GRB 051008
  93. GRB050922B: Swift UVOT early upper limits.
  94. GRB050801: Swift/UVOT Optical and UV detections
  95. Swift/UVOT photometry of GRB050730
  96. ROTSE-III prompt optical detections of GRB 030418
  97. GRB000926 Host Galaxy Observations

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