Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

3390 results found.

  1. GRB 160425A : MASTER earlier optical observations
  2. LIGO/Virgo G211117: EWE for NOWT of 12 days follow-up of northern sky
  3. GRB 160411A: Fermi GBM detection
  4. GRB 160411A: Swift detection of a short burst
  5. GRB 160410A: Swift/UVOT Detection
  6. GRB 160410A: Enhanced Swift-XRT position
  7. GRB 160410A: GROND optical detection
  8. GRB 160410A: Swift detection of a (possibly-short) burst with an optical counterpart
  9. GRB 160327A: Continued RATIR Optical and NIR Observations
  10. LIGO/Virgo G211117: LOFAR follow-up
  11. GRB 160327A: Swift-BAT refined analysis
  12. Swift detects GX 301-2 in very high state
  13. GRB 160321A: MASTER observations zero Galaxy latitude GRB
  14. Swift Trigger 678197 is a noise fluctuation
  15. LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
  16. GRB 160303A: BOAO R-band Detection
  17. GRB 160227A: LOAO 1.0m optical detection
  18. GRB 160227A: McDonald 0.8m Detection
  19. GRB 160228A: Mondy optcial observations
  20. GRB 160228A: MASTER-Amur prompt observations
  21. GRB 160227A: AROMA-N Optical Observation
  22. GRB 160228A: optical observations
  23. GRB 160225.81/FERMI Trigg 478121069: MASTER OT J095503.19-355149.4 detection
  24. GRB 160221A: Swift-XRT afterglow detection
  25. GRB 160221A: Swift-XRT observations
  26. GRB 160221A: MASTER-SAAO early observations
  27. GRB 160220A: MASTER-Amur observations
  28. LIGO/Virgo G211117: LOFAR follow-up
  29. GRB 160206A: MAXI/GSC detection
  30. GRB 160203A: TAROT La Silla - TAROT Calern - Zadko observations
  31. Fermi GBM trigger 475675010/160128498 is not a GRB
  32. GRB 160131A: Khureltogot optical observations
  33. GRB 160127A: LCOGT-Sutherland optical upper limit
  34. LIGO Virgo G211117: MWA Observations
  35. GRB160119A: BOOTES-2/TELMA Early Upper Limits
  36. GRB 160119A: Swift detection of a burst
  37. GRB 151228B: AbAO optical upper limit
  38. Konus-Wind observation of GRB 160113A
  39. IPN Triangulation of GRB 160113A
  40. LIGO/Virgo G211117: iPTF Observations of PS15dpn
  41. LIGO/Virgo G211117: VISTA imaging
  42. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  43. GRB 160104A: MITSuME Okayama upper limits
  44. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  45. LIGO/Virgo G211117: Gemini classification of 7 Pan-STARRS transients
  46. LIGO/Virgo G211117: LOFAR follow-up
  47. LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
  48. LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
  49. GRB 160102A: MAXI/GSC detection
  50. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28 - 30
  51. GRB 151231B: Fermi GBM observation
  52. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  53. LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
  54. LIGO/Virgo G211117: VLA follow-up
  55. Trigger 668877: Swift detection of V 404 Cyg
  56. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  57. V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations
  58. V404Cyg Swift Trigger 668097: AbAO optical observations
  59. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  60. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  61. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  62. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  63. GRB 151228B: Fermi GBM observation
  64. GRB 151228A: MITSuME Akeno optical upper limits
  65. GRB 151228A: T60 observations
  66. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  67. GRB 151228A: Fermi GBM observation
  68. LIGO/Virgo G211117: Pan-STARRS1 observations 2015-12-28
  69. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  70. GRB 151215A: Swift detection of a burst
  71. GRB 151205C: Optical follow-up observations at Kiso
  72. GRB 130831A: MASTER early OT detection and LC
  73. GRB 151205B: MASTER-NET early optical observations
  74. GRB 151205B: Swift detection of a burst
  75. Fermi GBM trigger 470375959/151128166 is not a GRB
  76. GRB151127A: Planned XMM-Newton observation
  77. GRB 151120A: Swift-XRT afterglow detection
  78. GRB 151120A: GROND optical/NIR afterglow
  79. GRB 151118A: ISON-NM early optical limit
  80. Swift-BAT trigger 663164 is not a burst.
  81. GRB 151107B: MASTER-NET OT detection inside the FERMI error box
  82. LIGO/Virgo G194575: Liverpool Telescope observations of iPTF-15dld and iPTF-15dni
  83. GRB 151107A: MASTER-NET optical observations
  84. GRB 151027A: Mondy optical observations
  85. GRB 151027A: Mt. Terskol observatory optical observation
  86. LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
  87. GRB 151031A: Swift detection of a burst
  88. GRB 151027A: Continued P60 Monitoring
  89. GRB 151027A: Optical counterpart detection
  90. GRB 151027A: SAO RAS optical observations
  91. GRB 151027B: LCOGT FTN afterglow observations
  92. GRB 151027A : Xinglong TNT optical observation
  93. GRB 151027A: continued GMG observation
  94. GRB 151027A: LCOGT-McDonald afterglow observations
  95. GRB 151027B: GROND Optical/NIR Afterglow Detection
  96. GRB 151027B: VLT/X-shooter redshift
  97. LIGO/Virgo G194575: Kanata/J-GEM optical follow-up
  98. LIGO/Virgo G194575: CQUEAN/LOAO observations
  99. LIGO/Virgo G194575: more details on transients from Pan-STARRS in the RA=1hr localisation region
  100. LIGO/Virgo G194575: transients from Pan-STARRS in the RA=1hr localisation region

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