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"

5544 results found.

  1. LIGO/Virgo G211117: LOFAR follow-up
  2. LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
  3. LIGO/Virgo G211117: MASTER OTs 26.XII.2015 - 01.I.2016
  4. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  5. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  6. LIGO/Virgo G211117: SkyMapper observations and transient candidate
  7. V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations
  8. GRB 151229A: MITSuME Akeno optical upper limits
  9. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  10. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  11. GRB 151229A: MITSuME Okayama upper limits
  12. GRB 151228B: MITSuME Akeno optical upper limits
  13. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  14. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  15. GRB 151228B: Swift detection of a burst with an optical detection
  16. GRB 151225A: CALET Gamma-Ray Burst Monitor detection of a possible short GRB
  17. V404Cyg Swift Trigger 668097:
  18. LIGO/Virgo G184098: Fermi-LAT search for high-energy gamma-ray counterpart
  19. GRB 151215A: MITSuME Akeno optical upper limits
  20. LIGO/Virgo G184098: LOFAR follow-up
  21. GRB 151205C: Optical follow-up observations at Kiso
  22. Swift detection of 4U 1850-03
  23. GRB 130831A: MASTER early OT detection and LC
  24. GRB 151205A: Swift detection of a burst
  25. GRB 151127A iTelescope observation
  26. LIGO/Virgo G184098: Results of of 2nd epoch of ASKAP follow-up
  27. Fermi GBM trigger 470290196/151127174 is not a GRB
  28. GRB 151127A: GROND K-band upper limit
  29. GRB 151127A: Swift detection of a short burst
  30. GRB 151027A: Maidanak optical observations
  31. Swift-BAT probable detection of an outburst from SGR J1819-1600 (AX J1818.8-1559)
  32. GRB 151118A: MITSuME Akeno optical upper limits
  33. GRB 151118A: AAO optical upper limit
  34. GRB 151114A: Swift detection of a burst with an optical counterpart
  35. GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
  36. GRB 151112A: MASTER-NET optical limit
  37. GRB 151111A: GROND marginal detection of a afterglow candidate
  38. LIGO/Virgo G194575: VLA follow-up
  39. GRB 151111A: LCOGT-FTS afterglow observations
  40. GRB 151111A: Swift-BAT refined analysis
  41. GRB 151111A: Enhanced Swift-XRT position
  42. GRB 151111A: Swift detection of a burst
  43. LIGO/Virgo G194575: La Silla QUEST, Pan-STARRS and PESSTO observations of iPTF15dld
  44. GRB 151027A: Mondy optical observations
  45. GRB 150910A: CrAO optical observations
  46. GRB 151027A: Optical counterpart detection
  47. GRB 151029A: LCOGT-FTS afterglow observations
  48. GRB 151027A: LCOGT-McDonald afterglow observations
  49. GRB 151027A: VLA detection
  50. GRB 151027A: THO optical observations
  51. LIGO/Virgo G194575: iPTF Optical Transient Candidates
  52. GRB 151027A: MITSuME Akeno Optical observation
  53. LIGO/Virgo G194575: GROND multi-color observations
  54. GRB 151027A: Weihai optical observations
  55. GRB 151027A : ISON-NM early optical detection
  56. GRB 151027A: KAIT optical afterglow confirmation
  57. GRB 151027A: Swift detection of a burst with a bright optical afterglow
  58. GRB 151006A: CALET Gamma-Ray Burst Monitor detection
  59. LIGO/Virgo G194575: Near-infrared follow-up with OAO-WFC
  60. LIGO/Virgo G194575: Kanata/J-GEM optical follow-up
  61. GRB 151021A: MITSuME Okayama upper limits
  62. LIGO/Virgo G184098: LOFAR follow-up
  63. Konus-Wind observation of GRB 151006A
  64. GRB 151006A: Fermi-LAT detection
  65. GRB 151006A: Fermi GBM detection
  66. GRB 151006A: MITSuME Okayama upper limits
  67. GRB 151006A: Prompt enhanced Swift-XRT position
  68. GRB 151006A: Swift detection of a burst
  69. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  70. Trigger 657564 / GRB 151004A: Swift BAT and XRT refined analysis
  71. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  72. Swift Trigger 657564: XRT prompt analysis
  73. LIGO/Virgo G184098: MASTER OTs detection and Scenario Machine prediction
  74. Swift Trigger 657564: a probable GRB
  75. LIGO/Virgo G184098: Ongoing gravitational-wave analysis
  76. GRB 151001B: Swift detection of a burst
  77. LIGO/Virgo G184098: spectral classification of PS15cci
  78. LIGO/Virgo G184098: Liverpool Telescope Spectroscopy of PS15ccx
  79. GRB 150925A: Swift detection of a burst
  80. LIGO/Virgo G184098: LOFAR follow-up
  81. LIGO/Virgo G184098: ASKAP followup
  82. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  83. LIGO/Virgo G184098: optical transient search with Kiso Schmidt telescope and KWFC on behalf of J-GEM collaboration
  84. LIGO/VIRGO G184098 : classifications of transients from the LSQ observations
  85. LIGO/Virgo G184098: INTEGRAL search of temporally coincident prompt hard X-ray emission
  86. LIGO/Virgo G184098: DESGW followup program
  87. LIGO/Virgo G184098: SkyMapper observations
  88. LIGO/Virgo G184098: TAROT network optical observations
  89. LIGO/Virgo G184098: MWA Followup
  90. LIGO/Virgo G184098: DESGW followup program
  91. LIGO/Virgo observing run 1 (O1) starts 2015-09-18 15:00 UTC
  92. LIGO/Virgo G184098: Keck II DEIMOS Spectra of iPTF Optical Candidates
  93. LIGO/Virgo G184098: Fermi-GBM ground-based follow-up
  94. LIGO/Virgo G184098: iPTF Optical Transient Candidates
  95. LIGO/Virgo G184098: VST-ESO PARANAL observations
  96. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  97. LIGO/Virgo G184098: observations by MASTER
  98. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  99. LIGO/Virgo G184098: Burst candidate in LIGO engineering run data
  100. GRB 150910A: AAO optical 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