Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

23435 results found.

  1. GRB 070129: VLT observations
  2. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  3. GRB 070129: Swift detection of a burst
  4. GRB 070126: Swift/UVOT refined analysis
  5. GRB 070125: optical observations
  6. GRB 070126: VLT observations
  7. GRB070126: Swift-XRT possible detection of an afterglow
  8. GRB070125: Optical observation by Kanata
  9. GRB070124: Swift-XRT Observation
  10. Possible GRB 070126: Swift/UVOT Upper Limit
  11. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  12. GRB 070125: Xinglong TNT optical observations
  13. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  14. GRB 070125: Lick 3m Spectroscopy
  15. GRB070125: Swift-XRT Refined Analysis
  16. GRB 070125: SARA detection in R
  17. GRB 070125: P60 Optical Afterglow Candidate
  18. GRB 070126?: Swift detection of a possible burst
  19. GRB070125 redshift request
  20. Konus-Wind observation of short hard GRB 070124
  21. IPN localization of GRB070124 (short duration, hard spectrum)
  22. Swift-BAT trigger 257213 is a Galactic Center transient
  23. GRB 070110: Continued Detection and Request for Ground Followup
  24. GRB 050904: Second Epoch of HST/NICMOS Observations
  25. GRB 070110: Ep,i - Eiso correlation
  26. GRB 070110 declared a "Burst of Interest" by Swift team
  27. Trigger 255685: Swift detection of a possible burst
  28. GRB 070110: UVOT Observations of a Candidate Afterglow
  29. GRB 070110, Swift-BAT refined analysis
  30. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  31. GRB 070110: Swift detection of a burst with a possible optical afterglow
  32. GRB070107: Swift/XRT refined analysis
  33. GRB 070107: Swift detection of a burst
  34. VLA observation of GRB 061222B
  35. VLA detection of GRB 061222A
  36. GRB070103: APO SPIcam i' and z' limits
  37. GRB 070103: Swift/UVOT Upper limits
  38. GRB070103: Swift XRT refined analysis
  39. GRB 070103: NOT observations
  40. GRB 070103: TAROT Calern observatory optical observations
  41. GRB 070103: Swift detection of a burst
  42. GRB061222a: optical observations
  43. erratum : SDSS Pre-burst Observations of GRB061126
  44. GRB 061210: Swift/XRT Astrometry Correction
  45. GRB 061222A: MITSuME Akeno optical upper limits
  46. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  47. GRB 061222B: MITSuME Akeno optical upper limits
  48. GRB 061222A: Xinglong Optical Limit
  49. GRB 061222A: Gemini Afterglow Candidate
  50. GRB061222A Swift/UVOT: Upper Limits
  51. GRB 061222B: Swift/UVOT Upper limits
  52. GRB 061222B: Observation with the KANATA 1.5m telescope
  53. GRB061222B: Swift-XRT Refined Analysis
  54. GRB 061222A: Observation with the KANATA 1.5m telescope
  55. GRB 061222B: BOOTES-IR optical observations
  56. GRB 061222B: SARA upper limit
  57. GRB 061222A, Swift-BAT refined analysis
  58. GRB 061222B: REM NIR/optical observations
  59. GRB 061222B: TAROT La Silla observatory optical observations
  60. GRB 061222B: Swift detection of a burst
  61. GRB 061222A: Prompt ROTSE-III Optical Limits
  62. GRB 061222: Swift detection of a burst
  63. GRB 061201: Magellan Redshift of nearby Abell cluster
  64. GRB 061218: TAROT La Silla observatory optical observations
  65. GRB 061217: TAROT Calern observatory optical observations
  66. GRB 061218: TORTOREM optical upper limits
  67. GRB 061218, Swift-BAT refined analysis
  68. GRB061217: VLT NIR observations
  69. GRB 061218, SMARTS optical/IR observations
  70. GRB 061218: REM prompt observations
  71. Swift triggers (#251863) on a possible burst
  72. GRB061217: Swift/UVOT refined analysis.
  73. GRB 061217: optical observations at Calar Alto
  74. GRB061217 - Swift/XRT refined analysis
  75. GRB 061217: Magellan Observations
  76. GRB 061217: REM prompt observations
  77. GRB 061217: ROTSE-III Optical Limits
  78. GRB 061217: Swift detection of a short hard burst
  79. GRB061210: Swift/UVOT observations
  80. GRB 061210: Swift XRT analysis - Possible counterparts
  81. GRB 061214(?): ROTSE-III Optical Limits
  82. GRB 061214(?): Swift detection of a possible burst
  83. GRB 061210: Gemini/GMOS Observations
  84. GRB 061126: Radio Observations
  85. GRB061210: Radio Observations
  86. GRB 061210, Swift-BAT refined analysis of the SHB
  87. GRB 061210: Swift-BAT detection of a short burst
  88. Optical Afterglow observations of GRB 061126
  89. GRB061126: update on the Swift-XRT afterglow light curve
  90. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  91. GRB 061202: TORTOREM optical upper limits
  92. GRB 061201: VLT optical decay
  93. GRB 061201: SOAR Confirmation of Candidate Afterglow
  94. GRB061202: FRAM early follow-up limit
  95. GRB061202 optical limit by "Pi of the Sky"
  96. Konus-Wind observation of GRB 061201
  97. GRB061202: optical/NIR observations with REM
  98. GRB061202: Swift/UVOT Upper Limits
  99. GRB 061202: Swift detection of a burst
  100. GRB 061201: VLT optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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