High Energy Network (HEN)

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Information on the observation and analysis of stars and other objects that are sources of x-rays and gamma rays.

67 301 By Bikeman 1 month 2 weeks ago

HEN NEWS 04/2024 (The one with multi-messenger astrology in it)

Affiliation
American Association of Variable Star Observers (AAVSO)
Bikeman Fri, 05/10/2024 - 19:39

I’d like to look back on April and highlight some things that might be of interest for HEN members. So let’s start with April 1st, Fools Day. There were some hilarious papers posted on arxiv, here are just a few examples:

1) Multi-Messenger Astrology : https://arxiv.org/abs/2403.19749

Yeah, why be limited to observations in the visual spectrum for astrology if we have so many more wavelengths to observe today. Makes perfect nonsense :-)

Black Hole - Neutron Star merger alert (especially for Australia)

Affiliation
American Association of Variable Star Observers (AAVSO)
Bikeman Tue, 04/23/2024 - 07:41

This is especuially of interest for Australian observers right now as the night starts on the East coast soon: https://gracedb.ligo.org/superevents/S240422ed/view/

 

For a prioritized list of target galaxies to observe, go to http://ned.ipac.caltech.edu/NED::GWFevents/ and select "S240422ed" from the drop down list

HEN News 03/2024 (The one with alphabet soup in it [O4, LIGO, KAGRA, VIRGO,...])

Affiliation
American Association of Variable Star Observers (AAVSO)
Bikeman Thu, 04/04/2024 - 21:16

There are news from the gravitational wave observatories: The planned pause in the O4 observation run is almost over, and the O3b part of the run is scheduled to resume on April 10th, 0800 Pacific time. Low latency alerts are already active already now. So it's time again to be prepared for the vent everybody is waiting for: an alert about the next Binary Neutron Star (BNS) merger event with sky localization that would allow amateurs and professionals alike to hunt down any optical counterpart!

Details can be found at https://observing.docs.ligo.org/plan/

Request to observe source of X-Ray flare (southern hemisphere)

Affiliation
American Association of Variable Star Observers (AAVSO)
Bikeman Fri, 03/08/2024 - 08:22

The KiloNova Catcher (KNC) project has requested a Target Of Opportunity observation for the southern hemispehere (Gravitational Wave detectors are currently offline so this is not related to a "kilonova" trigger from LIGO/VIRGO (the main "business" of KNC), but could still be very interesting)

An interesting X-ray flare was observed by the newly launched Einstein Probe https://www.mpe.mpg.de/7867826/EinsteinProbe and floowed up by observations of by Neil Gehrels/SWIFT which conformed a source. Deep (say, 18 mag and fainter) observations in the optical are requested.

AAVSO 0313+41

Affiliation
American Association of Variable Star Observers (AAVSO)
Degen1103 Sat, 02/03/2024 - 04:54

The question is about AAVSO 0313+41, well known Perseus A, or NGC 1275, or QSO B0316+413, or... In spite of noted AAVSO number, the object is not presented in VSX, unlike of such QSOs as BL Lac, MRK 421 or QSO B0954+658.

What is the reason? Large diffuse galaxy light obstructs photometry of active nucleus? Low variability? Or something other?

HEN News 02/2024 (The one with Scary Barbie in it)

Affiliation
American Association of Variable Star Observers (AAVSO)
Bikeman Sun, 01/28/2024 - 20:41

Soon after the Zwicky Transient Facility (ZTF) had recorded the optical transient ZTF20abrbeie, it became clear that this one didn't quite match any of the more frequent types of an extra-galactic transient like a supernova, Gamma Ray Burst afterglow or a common type of AGN outburst. The light curve and spectroscopy hinted that this one was very energetic, and probably of some rarer type.

HEN News 01/2024 (The one with Zooniverse and Chaos Computer Club in it)

Affiliation
American Association of Variable Star Observers (AAVSO)
Bikeman Thu, 01/11/2024 - 19:55

I'd like to start a series of semi-regular (say ca once every 2 weeks) series of news for the HEN forum subscribers here...if this catches on we could also maybe have semi-regular zoom meetings later, like other observing sections have now.

This week, I'd like to draw attention to a project that allows you to contribute to the science of Gamma Ray Burst from the comfort of an armchair:

https://www.zooniverse.org/projects/amylien/burst-chaser/about/research

Observing optical transients from Astro-COLIBRI alerts

Affiliation
American Association of Variable Star Observers (AAVSO)
pbenni Tue, 11/28/2023 - 19:39

Responding to an Astro-COLIBRI alert, I imaged the unclassified optical transient AT 2023yoa in M31 using a Rc filter.  My general question about optical transients - are there any archives interested in saving an optical transient image?  I signed up for Kilonova Catcher / GRANDMA but noticed they are selective on what events they wish to archive observer images.  Are these optical transients of scientific interest?  I understand that afterglows from gravity waves, gamma ray bursts, and bright supernovas are of interest, but GWs and GRBs are difficult to capture because of the large field

Candidate optical counterpart for extragalactic neutrino event

Affiliation
American Association of Variable Star Observers (AAVSO)
Bikeman Fri, 10/20/2023 - 22:21

There is a possible optical counterpart (a supernova of type Ibn) that seems consistent with a neutrino event.

https://www.wis-tns.org/object/2023uqf

 

Unfortunately the SN is quite dim  (ca 20 mag in V and R ) and fading already, so amateur observations will be difficult except for those with really huge scopes....but it might be interesting to follow events.

Here is the link to the search for related GCN circulars: https://gcn.nasa.gov/circulars?query=+IC231004A&limit=100