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"

3674 results found.

  1. GRB071104: NIR Afterglow Candidate at TNG
  2. GRB 071117: Swift-XRT revised position
  3. GRB 071112C: Optical and NIR data observed with KANATA
  4. Correction to the Swift-BAT Transient Identification (trigger=296683)
  5. GRB 071112C: Swift XRT refined analysis
  6. GRB 071112C: Optical observations at Crni Vrh
  7. GRB 071112C: Palomar Pre-Imaging
  8. GRB 071112C: Optical and NIR afterglows observed with KANATA
  9. GRB 071112C: Swift detection of a burst with an optical counterpart
  10. VLA IInd observation of INTEGRAL burst GRB 071109
  11. GRB0711101: Two new source from Xinglong TNT observation
  12. GRB 071101: Swift detection of a burst
  13. GRB 071028B Swift-BAT detection of a burst
  14. GRB 071028: SARA observations of variable source
  15. GRB 071028, Swift-BAT refined analysis
  16. GRB 071025: Kuiper Telescope Optical Observations
  17. GRB 060602A: host redshift
  18. GRB 071025a: PAIRITEL observations
  19. GRB 071020: Swift-XRT refined analysis
  20. GRB 071020: Swift detection of a bright burst
  21. GRB 071011: XRT afterglow detection
  22. VLA observation of GRB 070923
  23. GRB 070911: Swift detection of a burst
  24. GRB 070809: Swift detection of a short burst
  25. GRB 070808: ROTSE-III Optical Limits
  26. GRB 070808: Swift detection of a burst
  27. GRB 070805: Swift XRT initial analysis.
  28. Swift detection of a outburst from SAX J1810.8-2609
  29. GRB070721A: Swift/UVOT Detection of a Weak Afterglow
  30. GRB 070721A: optical observations
  31. GRB 070714B: Keck observations
  32. GRB 070721A: Swift/XRT refined analysis
  33. GRB 070714b ("Bastille"): Optical Pre-Imaging (Clarification)
  34. GRB 070714 ("Bastille"): Optical Pre-Imaging
  35. GRB 070714A, Swift-BAT refined analysis
  36. GRB 070714 : Liverpool Telescope optical counterpart ?
  37. GRB 070429B: NIR Observations
  38. GRB 070628: Watcher Observations
  39. OT20050728 was not an optical GRB afterglow
  40. GRB 070611, Swift-BAT refined analysis
  41. GRB 070529: Optical aterglow from MIRO
  42. GRB 070529: Swift detection of a burst with an optical aterglow
  43. GRB 070508: Optical afterglow detection
  44. GRB 070508: TAROT La Silla observatory optical observations
  45. GRB 070411 : Planned XMM-Newton observation
  46. GRB 070412: Swift detection of a burst
  47. GRB 070328 : Suzaku ToO follow up starts
  48. GRB070208: optical observations
  49. Short-Hard GRB 070209: PROMPT Observations
  50. GRB 070318: Swift detection of a burst with an optical afterglow
  51. GRB 070311: MDM Optical Detection
  52. GRB 070125: Chandra X-ray Confirmation of Jet Break
  53. GRB 070306: ART-3 early optical and near infrared constraints
  54. GRB 070306: IR observations and candidate afterglow
  55. GRB 070306, Swift-BAT refined analysis
  56. GRB 070306: XRT Team Refined Analysis
  57. GRB070306 - SDSS Pre-burst Observations
  58. GRB 070306: Swift detection of a burst
  59. GRB 070125, deep late-time optical observation
  60. VLA observation of GRB 070224
  61. GRB 070227: optical observations
  62. GRB 070227: optical observations
  63. GRB070227: possible X-ray afterglow detection
  64. GRB 070220 : Faulkes Telescope North optical limit
  65. GRB070208: optical observations
  66. GRB 070208: Early IR detection and afterglow astrometry
  67. GRB 070129: afterglow confirmation
  68. GRB 070125: further AAVSO optical observations
  69. GRB 070129: VLT observations
  70. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  71. GRB 070125: AAVSO optical observations
  72. GRB 070125: optical observations
  73. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  74. Retractions of previous Swift-BAT triggers
  75. GRB061222a: optical observations
  76. GRB 061222B: MITSuME Akeno optical upper limits
  77. GRB 061222: Swift detection of a burst
  78. INT+WFC observations of GRB 061126
  79. GRB 061126: Possible Jet Break
  80. GRB 061121: MDM Optical Decay
  81. RHESSI Spectrum of GRB061121
  82. GRB 061109: Swift detection of a possible burst
  83. GRB061019: second epoch CrAO observations
  84. GRB 061028: Swift/XRT Astrometry Correction
  85. GRB 061028: MDM Observations
  86. GRB 061028: P200 Observations
  87. GRB 061028: z band imaging
  88. GRB 061028: Swift/UVOT Observations
  89. GRB 061021, Swift-BAT Lag analysis
  90. GRB 060928: Swift observations
  91. GRB 060912, Swift-BAT refined analysis
  92. GRB 060904b: SMARTS optical/IR afterglow observations
  93. Two bright bursts from SGR 1806-20 detected with IBAS
  94. GRB060805 Liverpool Telescope observations
  95. GRB 060804: Swift-XRT Team Refined Analysis
  96. GRB 060804: Swift detection of a burst with a possible UVOT counterpart
  97. GRB 060728: Upper limits of the X-ray emission
  98. GRB 060719: Continued LCO optical observations
  99. GRB060717 - SDSS Pre-burst Observations
  100. Swift trigger 219136 is probably not a GRB

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