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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32725 results found.

  1. EP241021a: continued SOAR observations
  2. EP241101a: Optical upper limits with Kinder observations
  3. EP241101a: OHP/T193 optical observations
  4. EP241103a: Gemini optical limits
  5. EP241103a: EP observation update
  6. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  7. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  8. EP241103a: GSP optical upper limit
  9. EP241103A: LCO optical observations
  10. EP241103a: Global MASTER-Net observations report
  11. GRB 241030A: Rapid release of TESS data.
  12. EP241101a: Global MASTER-Net observations report
  13. GRB 241029A: GRBAlpha detection
  14. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  15. S241102cy: Identification of a GW compact binary merger candidate
  16. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  17. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  18. GRB241030A: OHP/T193 optical observations
  19. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  20. Swift GRB 241101A: Global MASTER-Net observations report
  21. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  22. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  23. EP241021a: Upper limit from Konus-Wind observations
  24. GRB 241101A: Swift-BAT refined analysis
  25. GRB 241030A: further SAO RAS optical observations
  26. GRB 241030A: Optical Observations via Virtual Telescope Project
  27. EP241021a: Liverpool Telescope optical follow-up observations
  28. GRB 241026A: SAO RAS optical observations
  29. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  30. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  31. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  32. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  33. EP241021a: OHP/T193 optical observations
  34. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  35. GRB 241030B: Montarrenti Observatory optical upper limit
  36. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  37. EP241026b: Liverpool Telescope optical follow-up
  38. GRB 241030A: SAO RAS optical observations
  39. GRB 241030A: Fermi GBM Observation
  40. EP241021a: AMI-LA radio detection
  41. GRB 241030B : GIT optical upper limits
  42. GRB 241030B: LCOGT Optical Upper Limits
  43. GRB 241030B: Swift-BAT refined analysis
  44. GRB 241030A: Swift-BAT refined analysis
  45. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  46. GRB 241030B: Swift/UVOT Detection
  47. EP EP241030a: Global MASTER-Net observations report
  48. GRB 241029A: LCO optical detection
  49. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  50. GRB 241030B: SVOM/GRM observation
  51. GRB 241030B : MITSuME Akeno optical upper limits
  52. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  53. GRB 241030B: SVOM/VT optical afterglow observations
  54. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  55. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  56. GRB241030B: Fermi GBM Observation
  57. GRB 241030B: BTA observations
  58. GRB 241029A: SVOM/VT optical afterglow observations
  59. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  60. GRB 241030B: optical observations from the INAF Asiago Observatory
  61. EP241021a: Swift-UVOT detection
  62. GRB241030B: GRANDMA/TAROT Upper Limit
  63. GRB 241030B: SAO RAS optical observations
  64. GRB 241030B: AKO Optical Afterglow Detection
  65. GRB 241030B: Nanshan/HMT optical afterglow detection
  66. GRB 241030B: SVOM/ECLAIRs detection of a burst
  67. Konus-Wind detection of GRB 241030A
  68. GRB 241030A: Fermi-LAT detection
  69. GRB 240912A: radio detection with the VLA
  70. Fermi GRB 241030A: Global MASTER-Net observations report
  71. GRB 241030A: AKO Optical Afterglow Detection
  72. Swift GRB 241030A: Global MASTER-Net observations report
  73. GRB 241030A: Swift/UVOT Detection
  74. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  75. GRB 241030A: SVOM/GRM observation
  76. GRB 241026A: Swift-BAT refined analysis
  77. GRB 241030A: SVOM/C-GFT optical observations
  78. GRB 241026A: LBT optical observations
  79. EP241021a: Optical rebrightening observations with Mephisto
  80. EP241026b: EP-FXT follow-up observation
  81. GRB 241030A: Multiband optical detection with Mephisto
  82. GRB 241030A: SVOM/VT optical afterglow observations
  83. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  84. GRB 241030A : MITSuME Akeno optical afterglow detection
  85. GRB 241029A: GROWTH-India Telescope optical follow up
  86. GRB 241030A: TRT optical observations
  87. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  88. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  89. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  90. GRB 241029A: SAO RAS optical observations
  91. GRB 241026A: SAO RAS optical observations
  92. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  93. EP241021a: SAO RAS observations of rebrightening
  94. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  95. EP241021a: ATCA radio observations
  96. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  97. GRB 241026A: Swift/UVOT Upper Limits
  98. GRB 241029A: Swift-XRT observations
  99. GRB 241029A: Fermi GBM Observation
  100. GRB 241029A: AKO Optical Afterglow Detection

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