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"

15717 results found.

  1. GRB 071013: optical observations at NOT
  2. GRB071013: optical limit
  3. GRB071010B, BVRcIc field calibration
  4. GRB 20071013: Xinglong TNT optical Upper Limit
  5. GRB 071011: Optical Limit after 13.95hrs
  6. GRB 071011: Xinglong TNT Optical afterglow observations
  7. GRB 071010B correction to GCN 6892 optical observations
  8. GRB 071011: Swift-XRT refined analysis
  9. VLA non-detection of GRB 071010A
  10. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  11. GRB 071011, Optical afterglow
  12. GRB 071011: Confirmation of P60 optical afterglow
  13. GRB 071010B: Optical Detection
  14. GRB 071011: Kanazawa Optical limits
  15. GRB 071011: P60 Optical Afterglow Candidate
  16. GRB 071011: MARGE Optical Limits
  17. GRB 071010B optical photometry
  18. GRB 071011: XRT afterglow detection
  19. GRB 071010B: Gemini Spectroscopic Observations
  20. GRB 071011: NAYUTA Optical Observation
  21. GRB 071010A: Continued Keck Imaging
  22. GRB 071011: Optical afterglow candidate
  23. Optical Observation: GRB 071010
  24. Optical observations: GRB 071010A
  25. GRB071010B: Swift/XRT detection
  26. GRB 071010A: bright NIR afterglow
  27. GRB071008: optical observations
  28. GRB 071010B possible optical transient
  29. GRB 071010: Swift-XRT observation
  30. GRB 071010 REM NIR observations
  31. GRB 071003: XRT refined analysis
  32. Radio detection of GRB 071003 with the VLA
  33. GRB 071003: VLT spectroscopy
  34. GRB 071003: Keck spectroscopy
  35. GRB 071003: Possible rebrightening
  36. GRB 071003 : Lulin R-band observations
  37. GRB 071003: Swift XRT position
  38. GRB 071003: OA power-law decay indices from KAIT
  39. GRB 071003 Optical observations
  40. GRB 071003: P60 Confirmation of Optical Afterglow
  41. GRB 071003: KAIT optical afterglow observations
  42. GRB 070911, SMARTS optical/IR afterglow observations
  43. GRB 070920B: ROTSE-III Early Optical Limits
  44. GRB 070920B: TAROT La Silla observatory optical observations
  45. INTEGRAL ToO observations of SGR1806-20
  46. GRB 070920b, SMARTS optical observation
  47. GRB 070917: Confirmation of the X-ray afterglow
  48. GRB 070920b: LCO optical observations
  49. GRB 070920B: NOT optical observations
  50. GRB 070920: TAROT Calern observatory optical observations
  51. GRB070917: Confirmation of optical afterglow
  52. GRB920925C: search for host galaxy
  53. GRB070917: optical observations
  54. GRB 070917: P60 Observations
  55. GRB 070917: KAIT optical limits
  56. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  57. GRB 070913: Afterglow candidate detected by TAROT La Silla observatory
  58. GRB 070913: SMARTS optical/IR observations
  59. GRB 070913: TAROT La Silla observatory optical observations
  60. GRB 070809: Confirmation of optical transient
  61. Observations of possible TAROT GRB transient near IC 4779
  62. Candidate Orphan GRB Optical Transient in IC 4779
  63. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  64. GRB070810b: optical candidate
  65. GRB 070810A: ROTSE-III Refined Analysis
  66. GRB 070810A: Continued Keck Imaging
  67. GRB 070810B: Keck spectroscopy of possible host galaxies
  68. GRB 070810: MASTER optical observation
  69. GRB 070809: Swift/UVOT Corrected Photometry
  70. Swift Alert 070810.8: MASTER optical observation
  71. GRB 070810A: Swift-BAT refined analysis
  72. GRB 070810B: Xinglong TNT optical Upper Limit
  73. GRB070810B: Optical observations with KANATA
  74. GRB 070810: Swift/UVOT Optical Counterpart
  75. GRB 070810: ROTSE-III Detection of Optical Counterpart
  76. GRB 070809: Optical Pre-imaging from Palomar
  77. GRB 070809: ROTSE-III Optical Limits
  78. GRB 070809: Swift detection of a short burst
  79. GRB 070808: OPTIMA-Burst optical upper limit
  80. GRB 070808: Xinglong TNT optical Upper Limit
  81. GRB070808: Optical observations with KANATA
  82. GRB 070808: ROTSE-III Optical Limits
  83. GRB070612A: Radio upper limit from GMRT
  84. GRB 070802: REM optical observations
  85. GRB 070802: Swift-XRT refined analysis
  86. GRB 070802: Confirmation of the optical afterglow
  87. GRB 070802: LCO optical observations
  88. GRB 070729: LCO optical imaging
  89. GRB 070721A: optical observations
  90. GRB 070724: optical observations
  91. GRB 070721B: further observations and analysis
  92. GRB 070721B: optical observations and proposed redshift
  93. Swift/UVOT observations of GRB070721B optical afterglow.
  94. GRB 070721B : Faulkes Telescope South observations
  95. GRB 070721A : Faulkes Telescope South optical limit
  96. GRB 070714B: confirmation of optical afterglow
  97. GRB070714B: Swift-XRT refined analysis
  98. GRB 070714b ("Bastille"): Optical Pre-Imaging (Clarification)
  99. GRB 070714 ("Bastille"): Optical Pre-Imaging
  100. GRB 070714 : Liverpool Telescope optical counterpart ?

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