Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

2852 results found.

  1. Detection of flare star Algol in Swift-BAT slew data
  2. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  3. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  4. GRB 080925: Suzaku WAM observation of the prompt emission
  5. GRB081001: SuperAGILE Localization of a long GRB
  6. GRB 080919: Swift-XRT refined analysis
  7. GRB 080919: REM NIR observations
  8. INTEGRAL ToO observation of SGR0501+4516
  9. Swift trigger 322590: BAT detection of a possible burst
  10. SGR 0501+4516: Swift XRT measure of the spin period
  11. GRB080823: Fermi Gamma-ray Burst Monitor detection
  12. GRB080805 optical limit by "Pi of the Sky"
  13. GRB 080805: Swift detection of a burst
  14. GRB 080725, Swift-BAT refined analysis
  15. GRB 080721, Swift-BAT refined analysis
  16. GRB 080721: Swift detection of a burst with a bright optical counterpart.
  17. Trigger 317393: Swift detection of a possible GRB
  18. GRB 080714: Swift detection of a burst
  19. GRB 080702B: Swift XRT and UVOT observations
  20. GRB 080701A: Early Super-LOTIS Observations
  21. Konus-Wind observation of GRB 080605
  22. GRB 080603B : Xinglong EST observations
  23. Konus-Wind observation of GRB 080603B
  24. GRB 080603B, Swift-BAT refined analysis
  25. GRB080604: confirmation of optical afterglow
  26. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  27. Swift analysis of BAT Slew Survey event (Trigger=009)
  28. GRB 080514B: UVOT Observations
  29. GRB 080514B: Swift-XRT analysis
  30. GRB 080514B: Afterglow candidate
  31. Konus-Wind observation of GRB 080507
  32. GRB 080430
  33. GRB 080420?: Swift detection of a possible short burst
  34. GRB 080413B: Rapid PROMPT Observations
  35. GRB 080413A: MOA-II optical afterglow observations
  36. GRB 080411: Swift-XRT Refined Analysis
  37. GRB080330: MAGIC telescope GeV observation
  38. GRB 080411: Swift detection of a bright burst
  39. GRB 080330: REM optical observations
  40. GRB 080330 Swift-UVOT refined analysis
  41. GRB 080330: Swift detection of a burst with an optical counterpart
  42. GRB 080325: NIR afterglow candidate
  43. GRB 080320: Early Super-LOTIS Observations
  44. GRB 080319B: Gemini-South photometry
  45. GRB 080319b light curve by Pi-of-the-Sky
  46. GRB 080319A: Swift detection of a burst
  47. Swift trigger 306323: Swift-BAT/XRT refined analysis
  48. GRB 080310: GAO 150cm telescope Optical Observation
  49. GRB 080310: RRM optical photometry with the VLT
  50. GRB080310: Super-LOTIS suggestion of brightening
  51. VLA possible radio detection of GRB 080229
  52. GRB 080229: Enhanced Swift-XRT position
  53. UVOT analysis for GRB080229
  54. GRB 080229: Swift detection of a bright burst
  55. GRB 080218: Swift detection of a burst
  56. Swift-XRT and UVOT observations of the IPN burst GRB 080211
  57. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  58. GRB 080205: GAO 150cm telescope Optical limit
  59. GRB 080129: TAROT La Silla observatory optical observations
  60. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  61. GRB 071125: Suzaku WAM observation of the prompt emission
  62. IPN triangulation of very bright GRB 071125
  63. GRB071104: NIR Afterglow Candidate at TNG
  64. GRB 071122: MASTER optical observation
  65. Correction to the Swift-BAT Transient Identification (trigger=296683)
  66. GRB071112C: Errata of MITSuME Ic band photometry
  67. GRB071112C MITSuME Okayama Optical Observation
  68. GRB 071112C: Palomar Pre-Imaging
  69. VLA prompt radio detection of the INTEGRAL burst 071109
  70. GRB 071104: Swift-XRT position
  71. GRB 071104: Gamma Ray Burst Localization by SuperAGILE
  72. GRB 071031: Swift detection of a burst with an optical counterpart
  73. GRB 071028: Swift detection of a burst
  74. GRB 071025: Kuiper Telescope Optical Observations
  75. GRB 071025: R/I-band update
  76. GRB071021 : CFHT Ks-band observation
  77. Possible radio detection of GRB 071021 with the VLA
  78. GRB 071021: correction to GCNC 6968
  79. GRB 071021: optical and NIR observations
  80. GRB 071021: Swift-XRT Team refined analysis
  81. GRB 071021: Faulkes Telescope South optical candidate
  82. GRB 071021: Swift detection of a burst
  83. GRB071010b: optical observations
  84. GRB 071010A: Continued Keck Imaging
  85. GRB 071010B: Bright OT confirmed with TLS
  86. GRB 071010, Swift-BAT refined analysis
  87. Konus-Wind observation of GRB 071006
  88. GRB 071010 REM NIR observations
  89. GRB 071010: Swift detection of a burst
  90. GRB 070810B: further XRT analysis
  91. GRB 071003: OA power-law decay indices from KAIT
  92. GRB 071003: KAIT optical afterglow observations
  93. GRB 070911, SMARTS optical/IR afterglow observations
  94. INTEGRAL ToO observations of SGR1806-20
  95. GRB 070913: Swift-BAT refined analysis
  96. GRB 070731, Swift-BAT refined analysis
  97. VLA upper limit on short hard burst GRB 070714B
  98. Konus-Wind observation of GRB 070724B
  99. GRB 070704, Swift-BAT refined analysis
  100. GRB 070628: Swift detection of a possible burst

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